Article

Do responsibly managed logging concessions adequately protect jaguars and other large and medium-sized mammals? Two case studies from Guatemala and Peru

April 2018
Biological Conservation 220:245-253

DOI:10.1016/j.biocon.2018.02.015

Authors:

Mathias Tobler

San Diego Zoo Widlife Alliance

Rony García-Anleu

Wildlife Conservation Society

Gabriela Ponce-Santizo

Wildlife Conservation Society

Show all 7 authorsHide

Large areas of tropical forest have been designated for timber production but logging practices vary widely. Reduced-impact logging is considered best practice and third-party certification aims to ensure that strict standards are met. This includes minimizing the number of roads constructed, avoiding sensitive areas and strictly regulating hunting. Large scale camera trap grids were utilized in Guatemala and Peru to evaluate the impact of reduced-impact logging in certified concessions upon the large and medium-sized mammal fauna with special emphasis on jaguars (Panthera onca). Spatial capture-recapture models showed that jaguar density in Peru (4.54 ± 0.83 ind. 100 km⁻²) was significantly higher than in Guatemala (1.52 ± 0.34 ind. 100 km⁻²) but in both regions, densities were comparable to protected areas. Camera traps detected 22 species of large and medium sized mammals in Guatemala and 27 in Peru and a multi-species occupancy model revealed that logging had no negative impact on any of the species studied and actually had an initial positive impact on several herbivore species. We found no avoidance of logging roads; in fact, many species, especially carnivores, frequently used logging roads as movement corridors. Our results indicate that well-managed logging concessions can maintain important populations of large and medium-sized mammals including large herbivores and large carnivores as long as hunting is controlled and timber volumes extracted are low. Responsible forest management would therefore be an ideal activity in the buffer zones and multiple use zones of protected areas creating much less impact and conflict than alternatives such as agriculture or cattle ranching while still providing economic opportunities. Logging concessions can also play an important role in maintaining landscape connectivity between protected areas.

Jaguar density in the forests of the Gran Calakmul Region, Mexico

Article

Full-text available

Mar 2025
J MAMMAL

The Jaguar (Panthera onca) is the largest felid in the Neotropics, and its population size and trends are poorly known. In this study, we estimated Jaguar density using camera traps and Spatially Explicit Capture-Recapture (SECR) models at 3 sites (Silvituc, Centenario, and Miguel Colorado) within the Gran Calakmul Region, a large and continuous forest area in southern Mexico. We also monitored temporal changes in Jaguar density at Miguel Colorado over a 5 yr period. Our results showed that the mean density at the 3 sites in 2018 was 2.245 jaguars/100 km2 and varied from 1.683 in Centenario to 2.635 in Miguel Colorado. We found that in Miguel Colorado—surveyed in 2018 and 2022—the estimated density was 2.635 and 2.00 jaguars/100 km2, respectively. We found no evidence of significant changes in Jaguar density over time at Miguel Colorado. We compared our estimates with those obtained by the Mexican National Jaguar Census (CENJAGUAR) and found that our estimates were lower than the lower bound of the confidence interval reported by CENJAGUAR for primary and secondary habitats on the peninsula but similar to those reported by other studies in the region using SECR. We extrapolated our density estimates from previously published potential habitat estimations in the Yucatan Peninsula Jaguar Conservation Unit (JCU) and obtained a population size ranging from 781 to 1,460 jaguars, depending on the habitat model used. These estimates are lower than the 2,092 jaguars reported by CENJAGUAR for the JCU, indicating that the population on the peninsula may be smaller than previously thought. Our study provides the most comprehensive and reliable Jaguar density estimates for the Gran Calakmul Region, probably the most important region for Jaguar conservation in Mexico. We highlight the need to monitor Jaguar populations periodically and to implement effective conservation actions to protect this emblematic species and its habitat in the Selva Maya.

Jaguar (Panthera onca) density and population size across protected areas and indigenous lands in the Amazon biome, its largest stronghold

Article

Full-text available

Feb 2025
BIOL CONSERV

Protected areas, including Indigenous Lands, play a critical role in protecting natural habitats and wildlife. The Amazon has a remarkable network of protected areas and is home to the largest population of the Neotropics' largest felid, the jaguar (Panthera onca). Yet, knowledge of the population status of jaguars across the biome is scarce. In this article, we use camera trap data combined with multi-session spatial capture-recapture models to estimate site-independent jaguar densities in 22 protected areas. Additionally, we tested for density spatial variation based on anthropogenic and biological variables, predicting approximate jaguar population size for each protected area sampled. The estimated average density of jaguars across our sites was 3.08 ± 1.13 individuals per 100 km2 but density estimates varied more than 20-fold from 0.60 ± 0.50 ind./100 km2 in the Lower Negro River (Cuieiras Biological Reserve) to 9.97 ± 2.48 ind./100 km2 in the várzea floodplains of the Amazon River (Sustainable Development Reserve Mamirauá). Our results revealed that the highest densities of jaguars occur in regions with higher primary productivity and that all 22 protected areas combined harbour an estimated jaguar population size of 6389 individuals (95 % CI: 4664-7986), highlighting the importance that protected areas have for the conservation of this emblematic species. We contend that implementing continuous monitoring programs across Amazonian protected areas and curbing escalating anthropogenic pressures is paramount to ensure these areas remain as a stronghold for the species.

Landscape and diel fear cycles: linear features are perceived as risky by peccary ( Dicotyles tajacu )

Article

Nov 2024

The risk of encountering a predator triggers different antipredator strategies in the prey, including spatial (landscape level), temporal (daily activity cycles), and behavioral changes. There is evidence that linear landscape attributes (e.g., dirt roads, firebreaks, trails) are used by both predators and prey, although studies examining how they react to mutual use are scarce. We propose a conceptual model that explains how prey might change their activity patterns under spatial-scale scenarios of predation risk. We test our predictions with Jaguar (Panthera onca) and Puma (Puma concolor) as predators and Collared Peccary (Dicotyles tajacu) as the prey. Peccary activity patterns differed between foraging areas with different levels of predation risk, with low-risk areas showing 2 peaks of activity around dusk, but exclusively diurnal in high-risk areas. The highest overlap coefficient (Δ^1 = 0.82) occurred when comparing peccary activity patterns near linear attributes and high-risk foraging areas, and the lowest (Δ^1 = 0.16) between high-risk foraging areas and Jaguar activity patterns, showing a completely diurnal pattern when the Jaguar was inactive. The overlap coefficient was intermediate (Δ^1 = 0.45) when comparing Puma and peccary activity patterns in high-risk areas. The observed similarity in peccary activity patterns between high-predation-risk foraging areas and linear attributes seems to indicate that the latter are also perceived as high-risk areas that lead to changes in their activity patterns.

Sunning behavior of five Accipitridae species in the Peruvian Amazon rainforest

Article

Sep 2024

We document 26 incidents of sunning behavior in 5 species of Accipitridae, including Crested Eagle (Morphnus guianensis), Black Hawk-Eagle (Spizaetus tyrannus), Ornate Hawk-Eagle (Spizaetus ornatus), Roadside Hawk (Rupornis magnirostris), and White Hawk (Pseudastur albicollis), during a camera-trap survey conducted in Madre de Dios, Peru, in 2014. The sunning behavior was observed in forest clearings along logging trails and on a dirt road. We recorded 2 high-intensity sunning postures: “full-spreadeagle”, in which the bird lies horizontally on the ground with wings outstretched, tail fanned, and head somewhat raised; and “full-spread,” in which the bird stands while holding its wings out at right angles to the body. Sunning is a maintenance behavior observed in many bird species and has been reported in Accipitriformes in various habitats, but it is not commonly observed in tropical rainforests because of low visibility. Our camera traps recorded sunning behavior from 0931 h to 1400 h, a period in which ambient temperature increased until reaching its maximum around 1400 h. The most likely function of sunning in Accipitriformes in the rainforest is an antiectoparasite strategy. Camera-trap monitoring has been useful in detecting unusual interactions and diel patterns of activity, and researchers can obtain a wide range of natural history, ecological, and behavioral insights that would be difficult to obtain using traditional methods. We recommend analyzing “bycatch” data from camera traps to recover information about bird behaviors that would otherwise be unattainable.

Jaguar (Panthera onca) population dynamics in an “isolated” national park in the Cerrado biome, Brazil

Article

Aug 2024

The jaguar (Panthera onca) is endangered throughout its geographical distribution, yet assessments of jaguar population dynamics are scarce. This study uses camera trap data from 4 surveys spanning 8 years to gain knowledge on jaguar population dynamics in Emas National Park (ENP), one of the largest protected areas in the Brazilian Cerrado biome, surrounded by large scale agriculture. We used spatially explicit capture-recapture models (SCR) to estimate jaguar density and population trends, and Cormack-Jolly Seber models (CJS) to estimate apparent survival. We derived estimates of recruitment into the independent population (adult and subadult) from population trends and survival estimates. Baseline detection rates were negatively affected by distance to river, higher for males than females, and on-road than off-road. The movement parameter σ was higher for males than females. Sex-ratio was slightly skewed towards females, and survey specific density estimates ranged from 0.14 (95% CI = 0.07 – 0.30) to 0.25 (95% CI = 0.13 – 0.46) ind./100km2, leading to an average annual population growth rate of 0.94 (95% CI = 0.82 – 1.06), i.e., a largely stable population. Survival was high (0.77; 95% CI = 0.57 – 0.89), and some individuals remained in the population for over 10 years, pointing towards a healthy population with low turn-over rates. However, recruitment into the independent population was low (0.19; 95% CI = 0.02 – 0.40), suggesting a somewhat isolated and saturated population. Our results highlight the importance of further conservation strategies to prevent population decline from anthropogenic pressures and stochastic factors.

Use of logging roads by terrestrial mammals in a responsibly managed neotropical rainforest in Guyana

Article

Sep 2023
FOREST ECOL MANAG

Selective logging is the most widespread use of tropical forests. Building logging roads facilitates access to previously remote rainforests, and so proper management is essential for ensuring biodiversity retention in logged landscapes. Terrestrial mammals often directly use logging roads (via movement corridors, hunting or foraging), making them vulnerable to poorly managed roads. Here we explore how the presence, arrangement and use of logging roads influence terrestrial mammal occupancy and detection within a Forest Stewardship Council (FSC) certified logged forest in Guyana. We compared camera trap data from20 natural 'game' trails in an unlogged area, with camera trap data from 23 sites set near to or on logging roads within the Iwokrama forest. Our findings showed high occupancy within logged areas with no statistically significant difference to unlogged areas. Higher detections were noted along secondary and feeder roads compared to skid trails and the natural trails in control areas. Additionally, our data showed a negative correlation between occupancy and distance to village for a scatter hoarding rodent, most likely driven by subsistence hunting by local communities. Our results indicate that proper road management geared towards the monitoring and guarded access of logging roads, can have a positive effect on terrestrial mammal occurrence within responsibly managed rainforests.

Mammal diversity and composition are not affected by certified timber extraction in Suriname

Article

May 2023
FOREST ECOL MANAG

Increasing knowledge of species occurrence and assemblage composition is crucial to uncover the impacts of human activities on biodiversity. Here we investigate the effects of certified selective logging on assemblages of medium-and large-sized mammals in central Suriname. Using camera traps set in logged and unlogged parts of two logging concessions, we estimated mammal richness and assemblage composition within them and compared the results to other sites across Suriname obtained from a literature search. Then, using Bayesian multi-species occupancy models, we investigated if selective logging affects the richness, composition, and probabilities of habitat use and detection of mammals in the study sites. We recorded 27 mammal species in total, of which four are threatened globally. The study areas were amongst the richest concerning mammalian diversity throughout Suriname in response to the larger sampling effort employed. However, assemblage composition was overall similar to other sites previously sampled in the country, with variation in species richness mainly driven by sampling effort. Species richness and assemblage composition were similar concerning logged and unlogged parts of the concessions. At the species level, only a minor influence was observed in the probabilities of detection and habitat use of mammals. Most species presented positive responses to logging status, i.e., increasing their detection and habitat use probabilities in logged sites. Therefore, we conclude that selective logging to the extent practiced in the managed sites may fulfill the criteria of sustainability. Due to the continuous nature of Suriname's landscape, which allows for a constant flow of species from managed to un-managed sites, it may act as a buffer to hamper the secondary and indirect impacts of selective logging.

Certified forest management and conservation of medium and large-sized mammals: biodiversity, trampling, browsing and seed removal in the Argentine Austral Yungas

Article

Apr 2023
FOREST ECOL MANAG

Timber extraction is one of the most widespread human activities in forested environments, and subsequent environmental degradation and impacts on wildlife have been extensively studied. Reduced impact logging under certification standards could help reconcile forest production with biodiversity conservation. However, whether this is a convenient strategy for the conservation of the medium and large-sized mammal assemblage of the Argentine Austral Yungas remains unknown. Here, we compared species richness, diversity and composition, sign frequency and species identity of medium and large mammals considering body mass and trophic guilds, as well as three mammal-plant interactions (seedling trampling, plant browsing and fruit removal) between an area under logging certification and a similar unlogged area (control). Our results indicate that, 3-4 years after logging stopped, 16 of the 32 variables analyzed showed no changes between the logged area and the control (species composition, richness and 2 diversity indices, frequency of herbivores and omnivores, frequency of 7 species, browsing rate in the 2 lowest strata and trampling rate). In the logged area, we found a higher frequency of medium-sized mammals and 5 mammals species, a higher browsing rate in the upper stratum and a higher fruit removal rate. However, we also found a lower frequency of carnivores, large mammals, and of six mammal species. Although in our study we found certain species-specific differences, with a predominance of generalist species and certain reduced biological interactions in the logged compared to the unlogged area, we propose that forest intervention under responsible management may help to conserve a significant proportion of medium and large-sized mammal diversity of the Argentine Austral Yungas. Effective forest management, which balances the conservation of natural resources with sustainable use, is a crucial solution to preserving biodiversity. Both environmental and governmental organizations should prioritize and support this approach as a way to mitigate deforestation and promote responsible use of our forests.

Jaguar (Panthera onca) population density and landscape connectivity in a deforestation hotspot: The Paraguayan Dry Chaco as a case study

Article

Full-text available

Sep 2022

The distribution of the jaguar has decreased by approximately 50% with its conservation highly dependent upon its persistence and mobility in anthropogenic landscapes. Consequently, understanding the effects of land use on jaguar populations and their connectivity is a necessary precursor for effective conservation of the species. We simultaneously estimated jaguar density and landscape connectivity in the ranching landscape of the Dry Chaco of western Paraguay, a deforestation hotspot, as a function of proportional forest area using spatial capture-recapture modeling. Using camera trap sampling at four sites along a deforestation gradient of 17%–51% area deforested, we estimated densities of 0.44–1.6 individuals/100 km², whereby densities and connectivity from the more deforested sites were significantly lower than those from the less deforested sites. Our results warrant concern for the long-term viability of jaguar in the Paraguayan Dry Chaco, highlighting the need for the effective implementation of existing national laws and management plans for the conservation of the jaguar and its habitat. Furthermore, we showed the importance of accounting for landscape heterogeneity typical of anthropogenic landscapes in the conservation of the jaguar, suggesting results from protected areas may be generating unrepresentative inferences for jaguars in general, while indicating the need to place a greater research emphasis on anthropogenic landscapes to meet range-wide conservation goals for the jaguar.

Towards sustainable futures for nature and people An appraisal report for Madre de Dios, Peru

Technical Report

Full-text available

Dec 2021

Mammal responses to reduced-impact logging in Amazonian forest concessions

Article

Sep 2021
FOREST ECOL MANAG

Production forests are a dominant feature of most tropical forest landscapes and it is therefore important to understand the effects of timber extraction on the resident fauna. Here we investigate the effects of reduced-impact logging (RIL) on medium-to large-sized terrestrial mammals in two Jamari National Forest logging concessions, southwestern Brazilian Amazonia. We used camera traps to survey the terrestrial mammal fauna. Bayesian multi-species occupancy models (MSOMs) were performed to assess the effect of logging intensity and density of logging roads on site-level species richness, occupancy and detection rates. Species richness was negatively affected by logging status and by increasing logging intensity, and positively affected by road density. Occupancy and detection rates of individual species were largely unrelated to model predictors, although responses across species tended to be consistent with that observed for species richness. Despite negative effects of logging on species richness, no individual species were lost at the landscape level, suggesting that concessions managed under RIL techniques may be a reasonable compromise between economic and conservation interests.

Jaguares en el corazón de la Selva Maya: fase III

Technical Report

Full-text available

Nov 2020

El Biotopo Protegido Naachtún Dos Lagunas (BPNDL), zona núcleo de la Reserva de la Biosfera Maya (RBM), es administrado por la Universidad de San Carlos de Guatemala (Usac). El jaguar (Panthera onca L.) por sus características ecológicas, grado de amenaza e importancia cultural fue seleccionado como Elemento Natural de Conservación, tanto del biotopo como de la reserva, por lo que es una especie de interés para la Usac como institución académica y como administrador. Como Elemento de Conservación, se debe contar con un monitoreo del jaguar que permita conocer tendencias poblacionales a través del tiempo. El objetivo general del proyecto fue generar insumos para el monitoreo de las poblaciones de jaguar como una herramienta para el manejo de la reserva, con énfasis en el BPNDL. Se compilaron los registros de P. onca en la base de datos del Centro de Datos para la Conservación (CDC) provenientes de estudios con trampas-cámara del 2013 al 2019. Se depuraron los catálogos de individuos de distintos estudios en uno solo y se actualizaron las estimaciones de densidad y abundancia absoluta realizadas por González y colaboradores (2019). Se identificaron 42 individuos de los cuales seis (tres hembras y tres machos) fueron clasificados como residentes, siendo este el primer registro de machos por tres años consecutivos en la RBM. Se empleó la aplicación oSCR para el desarrollo de modelos de captura recaptura espacialmente explícitos a partir de los cuales se estimó una densidad de 2 (.1) y 3 (.1) individuos/ 100 km2 para hembras y machos respectivamente.

Legal status, utilisation, management and conservation of the jaguar in South America

Article

Full-text available

Dec 2023

The jaguar Panthera onca is widely distributed throughout South America with its stronghold in the Amazon. It is protected by law in all countries, but some countries have legal loopholes and all lack a strict enforcement of the laws in place. Jaguar killing is common, even in strictly protected areas, but detailed records are lacking. Jaguars have been historically hunted for their pelts, however, inclusion of the species in the CITES Appendix I proved effective to curtail the spotted cat trade in the 1960s and 70s. Over the last few decades, there exists little information on jaguar hunting for trade, but recently reports have surfaced showing increased illegal trafficking of body parts with evidence of domestic and Asiatic demand. Conservation of jaguars in South America has been relatively well-informed by research data. National parks and indigenous lands have been and still are the cornerstones for jaguar conservation throughout the continent, but are hampered, with a few exceptions, by underfunding, understaffing and a lack of governance and political will. Financing the operation of national parks and protected areas, while securing rights of indigenous lands should be a priority for funding agencies, especially in areas where most jaguar populations are restricted to protected areas like Argentina and south-eastern Brazil. In countries where jaguars are still widespread efforts should also be directed toward unprotected areas where threats like habitat loss and killing are higher. There the biggest management challenge is upscaling conflict prevention and mitigation measures. The Jaguar 2030 Roadmap marks a milestone for the species, aiming to join range governments, NGOs and private partners to advance conservation action for jaguars, but getting the initiative off the ground is the current challenge. It is noteworthy to highlight the importance and need for transboundary cooperation and action, especially among the trans-frontier population hotspots. The new, or emerging threats like jaguar part smuggling and man-made fires need extra attention and action to be curtailed. If jaguar conservation is to be effective despite increasing threats, it needs to be streamlined from high level agreements through scalable effects on the ground, combining protected areas, corridors, and local people buy-in.

FSC forest certification effects on biodiversity: A global review and meta-analysis

Article

Jan 2024
SCI TOTAL ENVIRON

Patterns of Occupancy and Density of the Small Felids of Tropical America

Chapter

Nov 2023

The Neotropical realm harbors 9–14 species of small- and medium-sized felids, depending on taxonomic schemes. Some of these species are poorly known, and a few of them are globally threatened. Hierarchical models (HMs) have been developed to consider imperfect detectability in the process of modeling abundance and occupancy, thereby allowing for less biased inferences. Because of this, HMs have been applied to some of the Neotropical felids. Here, we conducted a literature review on abundance and occupancy studies conducted on small-/medium-sized felids of Tropical America. We found that most studies of abundance and occupancy have focused on ocelots (Leopardus pardalis), while the other species were mostly in multispecies studies. Tree cover was found to be influential for the occupancy of ocelots and tiger-cats (L. tigrinus), with jaguarundis (Herpailurus yagouaroundi) selecting areas closer to water and being less associated with dense vegetation cover. Density estimates through spatially explicit capture models were conducted on ocelots, margays (L. wiedii), and tiger-cats, with ocelots exhibiting densities much higher than the two smaller felids. We conclude by suggesting sampling schemes specifically targeted toward small felids abundance or occupancy, as several studies include these species as by-catch.

Environmental DNA metabarcoding as a useful tool for evaluating terrestrial mammal diversity in tropical forests

Article

Full-text available

May 2021
ECOL APPL

Innovative techniques, such as environmental DNA (eDNA) metabarcoding, are now promoting broader biodiversity monitoring at unprecedented scales, because of the reduction in time, presumably lower cost, and methodological efficiency. Our goal was to assess the efficiency of established inventory techniques (live‐trapping grids, pitfall traps, camera trapping, mist netting) as well as eDNA for detecting Amazonian mammals. For terrestrial small mammals, we used 32 live‐trapping grids based on Sherman and Tomahawk traps (total effort of 10,368 trap‐nights); in addition to 16 pitfall traps (1,408 trap‐nights). For bats, we used mist nets at 8 sites (4,800 net hours). For medium and large mammals, we used 72 camera trap stations (5,208 camera‐days). We identified vertebrate and mammal taxa based on eDNA analysis (12S region, with V05 and Mamm01 markers) from water samples, including a total of 11 3‐km transects for stagnant water sampling and seven small streams for running water sampling. A total of 106 mammal species were recorded. Building on sample‐based rarefaction and extrapolation curves, both trapping grids and pitfall were successful, recording 91.16% and 82.1% of the expected species for these techniques (~22 and ~9 species), and 16.98% and 6.60% of the total recorded mammal species, respectively. Mist nets recorded 83.2% of the expected bat species (~48), and 34.91% of the total recorded species. Camera trapping recorded 99.2% of the predicted large‐ and medium‐sized species (~31), and 33.02% of the total recorded species. eDNA recorded 75.4% of the expected mammal species for this technique (~68), and 47.0% of the total recorded species. eDNA resulted in a useful tool that saves on effort and reduces sampling costs. This study is among the first to show the large potential of eDNA metabarcoding for assessing Amazonian mammal communities, providing, in combination with conventional techniques, a rapid overview of mammal diversity with broad applications to monitoring, management and conservation. By including appropriate genetic markers and updated reference databases, eDNA metabarcoding method can be extended to the whole vertebrate community.

Jaguar ( Panthera onca ) density and tenure in a critical biological corridor

Article

Full-text available

Dec 2020

We estimated jaguar density and tenure, and investigated ranging behavior, using camera traps across the Maya Forest Corridor, a human-influenced landscape in central Belize that forms the only remaining connection for jaguar populations inhabiting two regional forest blocks: the Selva Maya and the Maya Mountain Massif. Jaguars were ubiquitous across the study area. Similar to the neighboring Selva Maya, mean density ranged from 1.5 to 3.1 jaguars per 100 km2, estimated by spatial capture-recapture models. Cameras detected almost twice as many males as females, probably reflecting detection bias, and males ranged more widely than females within the camera grid. Both sexes crossed two major rivers, while highway crossings were rare and male-biased, raising concern that the highway could prevent female movement if traffic increases. Jaguars were more transient where the landscape was fragmented with settlements and agriculture than in contiguous forest. Compared with jaguars in the protected forests of the Maya Mountains, jaguars in central Belize displayed a lower potential for investment in intraspecific communication, indicative of a lower quality landscape; however, we did detect mating behavior and juveniles. Tenure of individuals was shorter than in the protected forests, with a higher turnover rate for males than females. At least three-quarters of reported jaguar deaths caused by people were male jaguars, and the majority was retaliation for livestock predation. Jaguars seem relatively tolerant to the human-influenced landscape of central Belize. However, intensification of game hunting and lethal control of predators would threaten population persistence, while increased highway traffic and clear-cutting riparian forest would severely limit the corridor function. Our results show that the viability of the corridor, and thus the long-term survival of jaguar populations in this region, will depend on appropriate land-use planning, nonlethal control of livestock predators, enforcement of game hunting regulations, and wildlife-friendly features in future road developments.

Composition, Relative Abundance, and Diversity of Medium and Large Mammals in Tirba Lake Awi Zone, Ethiopia

Article

Full-text available

Apr 2023

Understanding the diversity, abundance, and habitat preferences of the fauna is essential for determining the status and suggesting effective conservation actions. A study was conducted in Tirba Lake Awi zone, Ethiopia, to evaluate the wealth, diversity, and composition of the medium and large mammal communities. It is also important to consider how these parameters differ from one habitat type to another and from one season to another. Researchers collected data using a transect method. As a result of the study, 330 individuals and 11 different species of mammals were identified across four orders and six families. The result shows that globally threatened species like the Leopard (Panthera pardus) were included. In terms of seasonal variation in wild mammal abundance, the difference was statistically significant (P

\le

0.001). A total of 330 ± 26.2 wild mammals were recorded, of which 180 ± 11 (55%) were observed during the wet season and 150 ± 6.5 (45%) during the dry season. Olive Baboons (Papio Anubis) accounted for 30.61% of the 11 mammalian species with 101 individuals, followed by Vervet monkeys (Cercopithecus aethiops) with 16.67% and 55 individuals, respectively. Mammalian populations were statistically significant among habitat types, with the highest similarity index (SI = 0.8) observed between open forests and shrubland, followed by shrubland adjacent to Cliff sites (SI = 0.7). The shrubland habitat type (Hʹ = 1) supports the greatest diversity of mammalian species, followed by the open forest habitat type (Hʹ = 0.8). In terms of diversity among habitat types, dense forests had the lowest Hʹ value (0.5). Based on the species similarity index, open forest and shrubland shared the most similarity of mammalian species (Sl = 0.8), while shrubland and cliff sites hosted the least similar species (SI = 0.7). To conclude, our findings contribute significantly to the conservation of Ethiopia's mammal populations. As a result of our findings, managers of the area will be able to make effective conservation decisions, and researchers wishing to conduct related studies will be able to use the findings as a baseline for their research. Studies in the study area have revealed that anthropogenic factors interact with the mammals in the area, putting them at risk. It is imperative that these animals are protected through an urgent conservation program.

FSC-certified forest management benefits large mammals compared to non-FSC

Article

Full-text available

Apr 2024
NATURE

More than a quarter of the world’s tropical forests are exploited for timber¹. Logging impacts biodiversity in these ecosystems, primarily through the creation of forest roads that facilitate hunting for wildlife over extensive areas. Forest management certification schemes such as the Forest Stewardship Council (FSC) are expected to mitigate impacts on biodiversity, but so far very little is known about the effectiveness of FSC certification because of research design challenges, predominantly limited sample sizes2,3. Here we provide this evidence by using 1.3 million camera-trap photos of 55 mammal species in 14 logging concessions in western equatorial Africa. We observed higher mammal encounter rates in FSC-certified than in non-FSC logging concessions. The effect was most pronounced for species weighing more than 10 kg and for species of high conservation priority such as the critically endangered forest elephant and western lowland gorilla. Across the whole mammal community, non-FSC concessions contained proportionally more rodents and other small species than did FSC-certified concessions. The first priority for species protection should be to maintain unlogged forests with effective law enforcement, but for logged forests our findings provide convincing data that FSC-certified forest management is less damaging to the mammal community than is non-FSC forest management. This study provides strong evidence that FSC-certified forest management or equivalently stringent requirements and controlling mechanisms should become the norm for timber extraction to avoid half-empty forests dominated by rodents and other small species.

Modelling jaguar gene flow in fragmented landscapes offers insights into functional population connectivity

Article

Full-text available

Jan 2024
LANDSCAPE ECOL

Context Preserving functional connectivity is a conservation priority to secure the long-term viability of geographically dispersed subpopulations, such as the jaguar (Panthera onca) populations in Central America. However, managing connectivity in this region is limited due to the scarcity of local assessments of the connectivity between existing populations, some of which exhibit low levels of gene flow and genetic admixture. Objectives We selected the jaguar as a model species to understand how gene flow of large carnivores is shaped in a heavily human-impacted landscape in the Neotropics. We assessed the impact of landscape features and spatial scale on jaguar gene flow across northern Central America, predicted synoptic, landscape-wide functional connectivity across the region; and compared connectivity predictions based on models of gene flow, habitat suitability, and expert knowledge. Methods We employed genetic data based on 335 faecal samples collected from 72 individual jaguars. We parameterized gene flow resistance surfaces using linear mixed effects models and the maximum likelihood population-effects method. We evaluated nine landscape variables at six spatial scales, selecting the optimal scale and transformation for each variable according to univariate models and AIC. To predict jaguar gene flow, we developed multivariate models and implemented resistant kernels to forecast functional connectivity between jaguar populations across the study region under three dispersal distance scenarios. Furthermore, we compared the connectivity estimates based on gene flow against those based on habitat suitability and the corridors delineated by expert knowledge in the region. Results Low resistance to jaguar gene flow was associated with greater tree cover and vegetation, lower areas of built-up, and intermediate distances from water bodies. Notably, tree cover affected jaguar gene flow on a smaller scale compared to the rest of variables. Higher connectivity, indicated by lower resistance, was found within and around the largest jaguar conservation units (JCUs) such as the Reserva-de-Biosfera-Transfronteriza, Selva-Maya and Maya-Mountains. This contrasted with the smallest JCUs, like Sierra-Santa-Cruz and Sierra-de-las-Minas in eastern Guatemala, and Cordillera-Nombre-de-Dios in Honduras. Across the region, lower connectivity was observed in the Caribbean connection between eastern Guatemala and midwestern Honduras, as well as in the Honduran and Nicaraguan Miskito area. Models based on gene flow and habitat suitability were similar in their predictions of areas of high connectivity; however, the habitat suitability models predicted larger areas of low connectivity than did the gene flow models. Moreover, the expert knowledge corridors were consistent with areas of high and medium connectivity as predicted by the gene flow model. Conclusions Gene flow of jaguars is positively driven by the presence of forest and water sources, while human impact (built-up and non-vegetation areas) has a negative effect. Areas of lowest resistance largely correspond to the location of JCUs, which serve as crucial reservoirs of high-quality jaguar habitat within the region. While the largest JCU in the region displayed high connectivity, the low connectivity between the smallest JCUs (i.e. Sierra-Santa-Cruz, Sierra-de-las-Minas and Cordillera-Nombre-de-Dios) underscores the need for conservation attention in these areas. Conservation and management actions such as habitat loss-prevention/restoration and anthropogenic impact mitigation should be prioritized in the binational region of Guatemala-Honduras, a key connectivity bottleneck between the species’ northern and southern ranges. Similarly, attention is warranted in the Honduran-Nicaraguan Miskito area.

Past, present and future of the jaguar: review of threats, solutions, and research and conservation needs

Article

Full-text available

Jan 2024

Jaguars Panthera onca in South America are now found in only about half of the area they occupied in the early 20th century, and the rate of their decline is still high. The two most important drivers of the current decline are: a) deforestation and other habitat transformation and fragmentation, and b) killing jaguars related to conflicts with cattle ranching. Other important threats include illegal hunting and trade in jaguar body parts, increasing road density, and the rapid expansion of uncontrolled mining. Among the most important conservation achievements obtained so far are legal regulations that have eliminated legal jaguar hunting and trade in their parts in all countries, and the establishment of a network of protected areas across the jaguar range. The most urgent problems to solve are effective solutions to stop deforestation and stop the killing of jaguars in areas of conflict with cattle ranching. More protected areas are needed; however, it is also necessary to improve the functioning of protected areas. Ecological corridors have to be properly identified and implemented. Other important needs include enforcement of laws to eliminate the illegal jaguar hunting and trade, implementation of a system of environmental education, and the development of ecotourism. A coherent and effective common system of nature protection across South America would help to achieve the conservation goals. A number of international conventions and agreements support the conservation of jaguars, and in the recent years, significant new international initiatives have arisen to elevate the profile of jaguar conservation. We present and discuss needs for research, conservation solutions, and actions to stop the decline of South America’s jaguars.

Distribution and status of the jaguar in the Guiana shield

Article

Full-text available

Dec 2023

With large tracts of intact forest, very low human population density, and limited road networks, the Guiana Shield supports jaguar Panthera onca populations across 99% of its historical range. Jaguars inhabit a diversity of forested habitats, from mangroves to mountain forest, with population density estimates ranging from 1.6 to 6.4 individuals/km². Protected areas cover 30% of the Guiana Shield and potential prey species are broadly distributed across the jaguar’s current range and do not constitute a limiting factor to its distribution. Habitat destruction, fragmentation, and degradation mainly linked to mining, unsustainable logging, land conversion for intensive agriculture and cattle pastures, retaliatory killing for depredation, and targeted hunting to supply an illegal trade in jaguar parts represent the primary threats to jaguar populations. Capacity for, and ability to, manage wildlife and wild lands must be improved to ensure that the current optimistic outlook for jaguar populations in the Guiana Shield does not diverge significantly with impending economic development.

Comparison of the conservation of medium and large-sized mammals in a national park and military area

Preprint

Full-text available

Nov 2023

National parks (NP) and military areas (MA) preserve natural ecosystems. Although both regions have positive and negative effects on animal communities, studies comparing their impacts on conservation are limited. We monitored mammalian communities using 21 sensor cameras in a MA (6 sites) and NP (15 sites) located on Gyeryongsan Mountain, South Korea from May to November 2021 to compare the conservation of medium and large-sized mammals between the two regions. Forty-one environmental variables, including anthropogenic and geographical factors, were extracted from different spatial ranges (50, 500, and 1000 m). A linear model and non-metric multidimensional scaling were used to identify the factors influencing community diversity. We also analyzed species habitat type preferences using a multispecies occupancy model and compared temporal activities in the two regions. Species diversity was similar between the two sites, with most animals preferring habitats with lower slopes located at greater distances from human trails. Only the Korean hare ( Lepus coreanus ) preferred the NP habitat of the eight species found. Active periods were similar for the species in both regions, except for differences in some carnivore species. Although not all species were affected by human activity, most preferred the MA over the NP. The carnivores were especially able to flexibly alter their active periods and locations in response to human activities, especially in the NP where human activity was more prevalent. Thus, strategies should be implemented to improve NP conservation success, such as spatial and temporal accessible and inaccessible section separation.

Using Camera-Trap Data to Simultaneously Estimate Jaguar (Panthera onca) Density and Resource Selection in the Paraguayan Dry Chaco

Chapter

Full-text available

Nov 2023

Habitat loss and human-caused mortality have led to an approximate 50% reduction of the distribution of the jaguar (Panthera onca). The large contraction in the jaguar’s occurrence points to a need to understand its population size and habitat preferences to apply to the species’ conservation. Typically, jaguar densities are estimated with capture–recapture modeling of photographic captures of individually identifiable individuals, while habitat selection is estimated from telemetry data. However, advances in spatial capture-recapture modeling now permit the simultaneous estimation of density and habitat selection based solely upon photographic detection data from camera-trapping grids. Here, we used data from 356 double camera-trap stations across five sites in the Paraguayan Dry Chaco to simultaneously estimate jaguar density and resource selection. We found that jaguar densities ranged from 0.58 to 1.39 individuals/100 km2. At the spatial scale of our analysis, jaguars showed a strong preference for forest cover, while space use was not affected by the Human Footprint Index. Our density estimates were consistent with previous estimates based upon a subset of our data, as well as with estimates for jaguar populations in other dryland ecosystems. Furthermore, the strong selection for forest was also consistent with range-wide patterns in jaguar space use and habitat selection derived from telemetry data. Due to extensive and ongoing deforestation in the Dry Chaco, combined with high human-caused mortality, the jaguar is critically endangered in Paraguay. Although we show that jaguars can persist in anthropogenically altered landscapes in Paraguay, their long-term survival at the national level is strongly dependent upon the effective enforcement of the national jaguar conservation law, and application of the national jaguar management plan, to mitigate negative population effects from habitat loss and human-caused mortality.

Selvas de Misiones

Chapter

Full-text available

May 2023

Not all roads are barriers: Large mammals use logging roads in a timber concession of south-eastern Cameroon

Article

May 2023
FOREST ECOL MANAG

In the literature, roads are often considered to be barriers for large vertebrates. In central Africa, the creation of roads and skid trails by logging operations leads to changes in the structure of forest landscapes that could influence wildlife movements. To assess the use of logging roads by six emblematic species of the central African forests, we conducted a camera trap (CT) survey on three types of tracks (secondary roads, skid trails, and elephant paths as control) in a logging concession of southeastern Cameroon. The relative abundance indices (RAI) of each species derived from the CT data were used in a mixed linear model to test the effects of four factors (type of track; time: day vs. night; gregariousness: alone vs. group; and time after logging: less than one year vs. between one and two years). The results showed no preference for any type of track for gorillas (Gorilla gorilla) and chimpanzees (Pan troglodytes). In contrast, significantly higher RAI on secondary roads were observed for buffalos (Syncerus caffer), forest elephants (Loxodonta cyclotis), and bongos (Tragelaphus eurycerus). For the last two, the difference was only significant if they were detected in the most recently logged areas, at night (for elephants), or alone (for bongos). We could not test for leopard (Panthera pardus) as we captured only two events. Although none of the species appear to avoid roads and skid trails, nor do they perceive them as a barrier, further studies should be conducted to increase sampling efforts over time and space to consider seasonality, vegetation growth after logging, geographical variability, and other anthropogenic influence. However, these first results reveal the importance of closing roads after logging to limit encounters between wildlife and humans and highlight the relevance of characterizing roads (type of road, width, surfacing, and canopy structure over the road) when studying their impact on wildlife.

Using acoustic recording units to investigate the effects of logging of indigenous trees in the Amathole forests, South Africa on Cape Parrot Poicephalus robustus breeding and the presence of three primary cavity-excavating bird species

Article

Full-text available

Apr 2023

The Amathole forest complex is the breeding stronghold of the endemic and vulnerable Cape Parrot Poicephalus robustus , and is also one of only two forest complexes in South Africa formally harvested for timber. The aim of this study was to determine if formal harvesting of indigenous trees, primarily the two yellowwood species Afrocarpus falcatus and Podocarpus latifolius, in 9 of 16 Amathole forests has had any effect on the presence of Cape Parrots and three primary nest-excavating species, as well as on parrot breeding. The study used logging data from the past 25 years (1997–2021) as well as data collected by acoustic recording units over two breeding seasons from 2019 to 2021. Cape Parrots were present in 15 of 16 forests, but breeding calls were identified in only seven forests: five in logged and two in unlogged forests. Fourteen of the forests harboured all three primary excavators: Knysna Woodpecker Campethera notata , Olive Woodpecker Dendropicos griseocephalus , and Red-fronted Tinkerbird Pogoniulus pusillus. The last two species were absent from the adjacent Mount Thomas and Kologha forests, respectively, in which parrots were present, but no breeding calls were recorded. Logging of yellowwoods was not found to affect parrot breeding. However, due to the overlap between preferred parrot breeding sites and preferred trees for harvesting, we recommend that harvesting in the five harvested forest blocks where parrot breeding occurs be limited to tree falls, with no standing dead, dying, or damaged trees harvested, to ensure that potential nesting trees are not harvested.

A Systematic Review of Logging Impacts in the Amazon Biome

Article

Full-text available

Jan 2023

Every year, logging in the world’s largest tropical forest, located within the Amazon biome, continues unabated. Although it is a preferred alternative to deforestation, the residual stand and site are impacted by logging. The objective of this review was to determine and assess the current state of research throughout Amazonia on the subject of logging impacts. To achieve this goal, a systematic approach was utilized to gather, assess and categorize research articles conducted in the Amazon biome over the last decade. Eligibility for inclusion of articles required demonstration of a direct impact from logging operations. A total of 121 articles were determined to meet the eligibility requirements and were included in this review. Articles were subdivided into three environmental categories: forest (n = 85), wildlife (n = 24) and streams (n = 12). The results of this review demonstrated that impacts from logging activities to the forest site were a direct result of the logging cycle (e.g., how often logging occurs) or logging intensity (e.g., how many trees are felled). The impacts to wildlife varied dependent on species, whereas impacts to streams were affected more by the logging system. Overall, research suggested that to attain sustainability and diminish the impacts from logging, a lower logging intensity of 10–15 m³ ha⁻¹ and a longer logging cycle of 40–60 years would be essential for the long-term viability of forest management in Amazonia.

Rainforest carnivore ecology in a managed forest reserve: Differential seasonal correlates between habitat components and relative abundance

Article

Dec 2022
BIOL CONSERV

Studies of relationships between seasons and Neotropical carnivore distributions tend to focus on water and prey availability without considering other habitat components such as escape, foraging, and resting cover. Our goal was to evaluate habitat characteristics that may be important for predicting the seasonal (dry or rainy) relative abundance of four commonly captured Neotropical carnivores (i.e., jaguar [Panthera onca], puma [Puma concolor], ocelot [Leopardus pardalis], and grey fox [Urocyon cinereoargenteus]) in Chiquibul Forest Reserve in Belize, Central America. We used trail camera data and random-effect Poisson models to investigate how prey ratios (number of prey detections/total detections), cover (e.g., logs and stumps used for hiding cover from predators), vegetation structure, and environmental site characteristics (e.g., site harvest-history, slope, aspect) were related to carnivore relative abundance. Both prey ratios and vegetation structure appeared in supported models more frequently than other environmental site characteristics and were negatively correlated with carnivore relative abundance. Supported models differed for each season for all species except jaguars for which mammalian prey ratios and prey cover at sites was always negatively correlated with jaguar relative abundance. Carnivores appeared to avoid sites where vegetation created ideal escape and hiding cover for prey even though prey may be less abundant. Our data suggest that vegetation structure and composition can create conditions conducive to carnivore foraging and that these characteristics can differ by season in the tropics.

Diversity, Abundance, and Habitat Association of Medium and Large-Sized Mammals in Tiski Waterfall, Awi Zone, Ethiopia

Article

Full-text available

Jun 2022

Abstract The reliable data on faunal diversity, abundance, and habitat preference is essential for proposing and establishing relevant conservation interventions. A survey was done from September 2019 to March 2021 to investigate the diversity, relative abundance, and habitat association of large and medium mammals in Tiski Waterfall, Ethiopia. Data was collected using the line transect survey method in both habitat types. In Cliff sites, the point transect was also used. The habitats were populated by large and medium animal species that favor Dense forest and Shrubland habitats near water sources. During the research, three different habitat categories were evaluated (Dense forest, Shrubland, and Cliff sites). Ten mammalian species were discovered. During the wet season, there were 243±6.6 populations recorded, while during the dry season, there were 204±6.8. Seasonal differences in species abundance were statistically significant (p≤0.001). The total populations of the three habitat types were 198.2 ±7.39, 135±5.35, and 114±5.16 for Dense forest, Shrubland, and Cliff site, respectively. All three habitat categories had a great difference in species abundance (p≤0.001). The Olive baboon (Papio anubis) was the most common, accounted for 38 percent of the population, followed by the Vervet monkey (Cercopithecus aethiops), which accounted for 23 percent. Leopard (Panthera pardus) and Common Bushbuck (Tragelaphus scriptus) contributed the least to the total, accounting for only 2% each of the total. The highest diversity of mammalian species was found in Dense forest (H' = 0.98), followed by Shrubland (H' = 0.90), and the Cliff location has the lowest diversity (H' = 0.57). The maximum uniformity of the species was found in Dense forests (J = 0.51), followed by a shrub region (J = 0.43), and the remaining of the habitat was (J = 0.35). Dense forest and Shrubland had the highest species similarity (Sl = 0.67), followed by Shrubland and Cliff site (SI = 0.61). In Dense forests with Cliff sites, the similarity was lowest (SI = 0.31) in each. To limit the impact of agricultural growth on big and medium mammals, good habitat management is required.

Landscape patterns in the occupancy of jaguars ( Panthera onca ) and their primary prey species in a disturbed region of the Selva Maya in Mexico

Article

May 2022

In order to prioritize the conservation and management efforts to protect jaguars ( Panthera onca) , it is of utmost importance to determine their tolerance in face of human disturbances, habitat modifications and varying degrees of prey availability. We assessed the occupancy probability of jaguars and five of their most common prey species throughout a heterogeneous landscape in the Selva Maya in southern Mexico: armadillo ( Dasypus novemcinctus ), coati ( Nasua narica ), paca ( Cuniculus paca ), white-tailed deer ( Odocoileus virginianus ), and collared peccary ( Dicotyles tajacu ). Additionally, we projected prey and Jaguar occupancies onto a 5993 km ² landscape based on the habitat type in the area. We averaged the best prey models ranked by QAICc and found that white-tailed deer had the highest average occupancy probability of 0.72 ± 0.06 and paca the lowest with 0.14 ± 0.04. The average occupancy probability for jaguars was 0.35 ± 0.07 and the strongest predictor of jaguar occupancy was a positive effect of collared peccary occupancy. These findings support previous studies that show that predator distribution is largely influenced by their prey availability, even in the midst of degraded habitats, and underlies the essential need to incorporate protection plans for prey species in jaguar conservation strategies.

Reducing the Barriers of Acquiring Ground-truth from Biodiversity Rich Audio Datasets Using Intelligent Sampling Techniques

Conference Paper

Full-text available

May 2022

The potential of passive acoustic monitoring (PAM) as a method to reveal the consequences of climate change on the biodiversity that make up natural sound-scapes can be undermined by the discrepancy between the low barrier of entry to acquire large field audio datasets and the higher barrier of acquiring reliable species level training, validation, and test subsets from the field audio. These subsets from a deployment are often required to verify any machine learning models used to assist researchers in understanding the local biodiversity. Especially as many models convey promising results from various sources that may not translate to the collected field audio. Labeling such datasets is a resource intensive process due to the lack of experts capable of identifying bioacoustics at a species level as well as the overwhelming size of many PAM audiosets. To address this challenge, we Tackling Climate Change with Machine Learning workshop at NeurIPS 2021 have tested different sampling techniques on an audio dataset collected over a two-week long August audio array deployment on the Scripps Coastal Reserve (SCR) Biodiversity located adjacent to sandstone cliffs and the Pacific Ocean in La Jolla, California. These sampling techniques involve creating four subsets using stratified random sampling, limiting samples to the daily bird vocalization peaks, and using a hybrid convolutional neural network (CNN) and recurrent neural network (RNN) trained for bird presence/absence audio classification. We found that a stratified random sample baseline only achieved a bird presence rate of 44% in contrast with a sample that randomly selected clips with high hybrid CNN-RNN predictions that were collected during bird activity peaks at dawn and dusk yielding a bird presence rate of 95%. The significantly higher bird presence rate demonstrates how intelligent, machine learning-assisted selection of audio data can significantly reduce the amount of time that domain experts listen to audio without vocalizations of interest while building a ground truth for machine learning models.

Occupancy models reveal potential of conservation prioritization for Central American jaguars

Article

Full-text available

Mar 2022
ANIM CONSERV

Understanding species‐environment relationships at large spatial scales is required for the prioritization of conservation areas and the preservation of landscape connectivity for large carnivores. This endeavour is challenging for jaguars (Panthera onca), given their elusiveness, and the local nature of most jaguar studies, precluding extrapolation to larger areas. We developed an occupancy model using occurrence data of jaguars across five countries of Central America, collected from camera‐trap studies of 2–12 months' duration, deployed over an area of 14 112 km² from 2005 to 2018. Our occupancy model showed that habitat use of jaguars increased with primary net productivity and distance to human settlements, and distance to rivers. Detection of the species was related to survey effort and research team identity. Within the jaguar extent of occurrence, 73% was deemed suitable for the species, with 47% of it lying within Jaguar Conservation Units (JCU) and 59% of JCU land being legally protected. Suitable areas were divided into four distinct clusters of continuous habitat shared across country borders. However, large areas of predicted low habitat suitability may constrict connectivity in the region. The reliability of these spatial predictions is indicated by the model validation using an independent dataset (AUC = 0.82; sensitivity = 0.766, specificity = 0.761), and concordance of our results with other studies conducted in the region. Across Central America, we found that human influence has the strongest impact on jaguar habitat use and JCUs are the main reservoirs of habitat. Therefore, conservation actions must focus on preventing habitat loss and mitigating human pressure, particularly within the clusters of continuous areas of high suitability, and on restoring habitat to foster connectivity. The long‐term persistence of jaguars in the region will depend on strong international cooperation that secures jaguar populations and their habitat across Central American borders.

Narratives of Tourism and Conservation

Chapter

Dec 2021

Margit Ystanes

This chapter explores the proposal to develop a new reserve in the Maya Biosphere Reserve financed by Mirador Basin tourism as it has been presented to the public throughout the years. This alternative vision for conservation and development was initially presented through Alfonso Portillo’s 2002 Presidential Decree and more recently to Bill S-3131, which was presented to the US Congress in 2019. This chapter explores the contents of these plans, how they are promoted and the critiques against them. Through analysis of the narratives used to make the case for Mirador Basin tourism, this chapter argues that their intersection with global discourses on saving tropical forests makes these narratives more trustworthy to Euro-American publics than to local concessionaires.

Retrospective and current trend of wild‐cat trade in Peru

Article

Full-text available

Oct 2021

Several species of wild cats are threatened with extinction due to habitat loss, persecution or retaliatory killing by humans as a result of real or perceived livestock depredation, and illegal trade. The trade of individuals or their parts has been a recurring threat over the years, especially prior to the establishment of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) in 1975. We assessed the extent of trade of wild cats in Peru (eight species) using export records available from 1946 to 1973, before the establishment of CITES and after the implementation of CITES using confiscation data available for 2001–2020. The ocelot and the jaguar were the most exploited species for their skins in the pre‐CITES period, with 228,376 and 17,301 individuals, respectively; as well as post‐CITES, although at significantly lower levels, with 67 individuals and 107 body parts, and 27 individuals and 99 body parts, respectively. Post‐CITES trade, however, shows an increasing trend for the jaguar and all wild cat species. Currently in Peru, the illegal wildlife trade is considered opportunistic, but its impact on wild populations has not been properly documented. We recommend improving knowledge regarding population status of wild cats to inform conservation status, and to increase efforts to reduce illegal trade at both national and regional level. Jaguars and ocelots were the most exploited species for their skins in the pre‐CITES period. Currently, illegal trade of wild cats is well below the pre‐CITES period.

Extensive aquatic subsidies lead to territorial breakdown and high density of an apex predator

Article

Full-text available

Nov 2021
ECOLOGY

Energetic subsidies between terrestrial and aquatic ecosystems can strongly influence food webs and population dynamics. Our objective was to study how aquatic subsidies affected jaguar (Panthera onca) diet, sociality, and population density in a seasonally flooded protected area in the Brazilian Pantanal. The diet (n = 138 scats) was dominated by fish (46%) and aquatic reptiles (55%), representing the first jaguar population known to feed extensively on fish and to minimally consume mammals (11%). These aquatic subsidies supported the highest jaguar population density estimate to date (12.4 jaguars/100 km²) derived from camera traps (8,065 trap nights) and GPS collars (n = 13). Contrary to their mostly solitary behavior elsewhere, we documented social interactions previously unobserved between same‐sex adults including cooperative fishing, co‐traveling, and play. Our study demonstrates that aquatic subsidies, frequently described in omnivores, can also transform the ecology and behavior of obligate carnivores.

Jaguar distribution, biological corridors and protected areas in Mexico: from science to public policies

Article

Full-text available

Nov 2021
LANDSCAPE ECOL

Context Land use change, habitat loss and fragmentation are the major threats to jaguar conservation in Latin America. Here, we integrate the information of jaguar’s distribution to identify priority areas for its conservation. Objective We evaluated the effect of topographic, anthropogenic and landscape variables on habitat suitability to evaluate potential core areas and biological corridors for jaguar conservation across Mexico. Methods We compiled a database of jaguar occurrence records, geospatial data-set of all Natural Protected Areas and using the expert criterion of the Mexican jaguar specialists to define Jaguar Geographic Regions; i.e. well-defined large units with similar ecological characteristics across the geographic range of jaguars in Mexico. We then conducted analyses of ecological niche models to identify Jaguar Conservation Units; i.e. core units with jaguar populations of 15 or more individuals. We used Least Cost Path and Circuit Theory analyses to define the Biological Corridors; i.e. regions with enough habitat to allow for jaguar dispersal along their geographic range, but putting emphasis in connecting Jaguar Conservation Units. Results We identified 5 Jaguar Geographic Regions (JGRs), 10 Jaguar Conservation Units (JCUs), and 13 Biological Corridors to maintain the connectivity of jaguar’s populations across their whole geographic range in Mexico. Our results showed that JGRs cover 25% of the country but only 21% of those regions are currently protected in nature reserves. So, our study illustrates the importance of the creation of new protected areas or the implementation of other schemes of conservation to protect larger extensions of the jaguars’ habitat in Mexico. It also indicates that despite the reduction of jaguar range in Mexico, there are still relatively large and well conserved areas capable of maintaining jaguar populations. Conclusions Our results are a fundamental tool to guide the conservation and management of jaguars in Mexico. Our findings indicate that public jaguar conservation policy to protect the remaining jaguar habitat in Mexico should include the following actions: i) Strengthen established protected areas, ii) Create new protected areas, iii) Implement sustainable development programs to stimulate land owners to protect their lands, and iv) Develop mitigation measures for infrastructure. Although the window of opportunity is closing, our results indicate that there is still time to save jaguars and the plethora of species that share their habitat in Mexico.

Extensive aquatic subsidies lead to territorial breakdown and high density of an apex predator

Preprint

Full-text available

Mar 2021

Energetic subsidies between terrestrial and aquatic ecosystems can strongly influence food webs and population dynamics. Our objective was to study how aquatic subsidies affected jaguar (Panthera onca) diet, sociality, and population density in a seasonally flooded protected area in the Brazilian Pantanal. The diet (n = 138 scats) was dominated by fish (46%) and aquatic reptiles (55%), representing the first jaguar population known to feed extensively on fish and to minimally consume mammals (11%). These aquatic subsidies supported the highest jaguar population density estimate to date (12.4 per 100 km2) derived from camera traps (8,065 trap nights) and GPS collars (n = 13). Contrary to their mostly solitary behavior elsewhere, we documented social interactions previously unobserved between same-sex adults including cooperative fishing, co-traveling, and play. Our research demonstrates that aquatic subsidies seen in omnivores can be highly influential to obligate carnivores leading to high population density and altered social structure.

Andean bears below the Andes

Article

Oct 2024

Unravelling the effects of individual heterogeneity on connectivity estimates: Insights from Spatial Capture-Recapture modelling

Preprint

Full-text available

Mar 2024

Spatial Capture-Recapture (SCR) models, parametrized with least cost path distance, provide a unifying framework for explicit estimating landscape connectivity and population size from individual detection data. However, we frequently encounter individuals with larger apparent space use than the rest of the population. To avoid biased population size estimates, it is common practice to remove these outliers from the analysis. Yet such individuals are likely to be very important when the aim is to estimate connectivity. We therefore investigated how unmodelled individual heterogeneity in space use affects population size and connectivity estimates from SCR models. We first conducted a simulation study. We varied the proportion of the population whose space use is most constrained by landscape structure. We fit four SCR models, increasing the degree of modelled individual heterogeneity to assess its effect on parameter estimates. Secondly, we applied these models to the Pyrenean brown bear population, examining the effects of removing outliers or modelling explicitly heterogeneity on parameter estimates. Our simulation study showed that population size was underestimated when no individual heterogeneity was modelled and increased with increasing the level of individual heterogeneity modelled. Moreover, unmodeled individual heterogeneity led to biased connectivity estimates towards the group, which is the most detected. In our case study, modelling individual heterogeneity was key to unravel the patterns in population space use. Female brown bear movements were restricted by road density (estimated resistance: alpha (squared) = 0.27 [0.01, 0.43]), whereas a small group of males were not affected by road density (alpha (squared) = -0.16 [-0.64, 0.24]). Our study provides valuable insights for optimizing the application of SCR models. When the primary objective is to accurately estimate population size, we recommend removing outlier individuals with larger home range sizes to avoid the risk of underestimating population size. Conversely, when the aim is to assess landscape population-level connectivity, modelling individual heterogeneity is essential. Our findings underscore the importance of tailoring the SCR model to the specific research goal, ensuring more precise and meaningful ecological inferences.

High mammalian diversity on the Las Piedras River tributary of Madre de Dios, Peru: An annotated list of species including comments on biogeography and regional conservation.

Article

Full-text available

Jan 2024

Several mammal inventories have been reported from the lowland Amazon of Madre de Dios, Peru, but few have been reported for the Las Piedras River. Here we present a list of mammal species from the Las Piedras River. Over a period of seven years (2013–2020), we recorded the presence of mammal species, excluding bats and small rodents, using camera traps and opportunistic sightings. Our study area was near the Huascar-Las Piedras River conﬂuence, 58 km north of the Madre de Dios River and covering an area of 22,430 ha. We recorded 60 species belonging to seven orders, 26 families, and 53 genera, including novel records for the Las Piedras tributary. Notable records reported include Leopardus cf. tigrinus (Schreber, 1775), Galictis vittata (Schreber, 1776), Saguinus imperator subgrisecens (Lönnberg, 1940), Cebuella niveiventris (Lönnberg, 1940), Cyclopes thomasi (Linnaeus, 1758), Coendou ichillus Voss & da Silva, 2001, and Caluromys lanatus (Olfers, 1818).

Jaguar conservation status in north-western South America

Article

Full-text available

Dec 2023

We analysed the current conservation status of the jaguar Panthera onca in north- western South America (7.14 million km2 in total). The area is composed of habitats belonging to three eco-regions: the Andes, the Llanos, and the Amazon. Based on a large set of jaguar presence-absence data and a species distribution model, we estimated the current jaguar range at 4.98 million km2, which represents 78.6% of the historical jaguar range in this region. The countries where jaguar range has shrunk most are north-western Venezuela, Ecuador and Colombia. Across the region, protected areas cover 27% of the jaguar range and indigenous territories 25%, with Ecuador having the highest and north-west Venezuela the lowest percentage of jaguar range under protection. Jaguar densities vary across the region, from 0.3 jaguars/100 km2 in the driest or most degraded parts to 4.0–7.3 jaguars/100 km2 in humid, productive, and best- preserved habitats of the Amazon Basin and Venezuelan Llanos. Based on combined density and updated distribution models we estimate a total jaguar population at 105,000 jaguars (95% CRI: 81,200–128,800) for the region, with mean density of 2.1 jaguars/100 km2. Jaguar diet varies by habitat, from arboreal mammals and aquatic reptiles (mainly caimans) in the ‘varzea’ floodplain forests of Central Amazon, to large and medium- sized mammals in upland tropical forests and in the Llanos, with peccaries, capybaras, and occasionally livestock being the most important prey species. The main threats for jaguars in the region are deforestation and fragmentation of habitats, human-jaguar conflict, poaching (increasing due to the growing demand for jaguar parts from the Asian market), infrastructure expansion, and mining. The most important conservation goals are to halt deforestation, reduce the killing of jaguars for retaliation and trade, increase the number of protected areas, protect ecological connectivity, improve law enforcement, and implement a better system of environmental education.

Two systematic literature reviews of scientific research on the environmental impacts of forest certifications and community forest management at a global scale

Article

Jan 2023
FOREST POLICY ECON

Forest certifications (FCs) and community forest management (CFM) are two major forest governance interventions whose aim is to reverse forest degradation and deforestation, while providing socio-economic benefits to the people involved. Despite being applied for more than a quarter of a century, there is a dearth of scientific evidence on the environmental impacts in the long- and short-term that these governance interventions have on the ground. Evidence is also needed to elucidate the governance mechanisms and contextual factors that facilitate the achievement of positive impacts. To fill these knowledge gaps, we conducted two systematic literature reviews (SLRs) comprising sixty-five publications in total, which collectively cover a total forest area of around 19 million hectares. Of these publications, only thirteen can be considered ‘sufficiently rigorous’ according to CEE and 3ie standards. The evidence of the reported environmental impacts of both FCs and CFM nonetheless shows clear trends towards (strong) positive impacts on the ground, with only six studies reporting no impact and only two studies, concerning FCs, reporting negative impacts. However, given the small sample size of the (rigorous) publications, we cannot make strong generalizing statements about the impacts that these interventions actually have on the ground. Moreover, both SLRs highlighted serious evidence gaps concerning the impacts that both forest governance interventions have on fauna and ecosystem services. Governance mechanisms most associated with positive impacts in the SLR on FCs were ‘institutions’, whereas for CFM the combination of ‘institutions’, ‘incentives’ and ‘information’ appears to be necessary to see positive impacts. As far as additional contextual factors are concerned, the political environment in which FCs are being implemented emerged as one important enabling factor for achieving positive impacts, together with the biophysical characteristics of the forests. For CFM, a combination of contextual factors already identified by the work of IFRI (2015) enables positive impacts, namely resource system characteristics, user group characteristics, and the biophysical characteristics of the forests.

Assessment of jaguars Panthera onca (Mammalia: Carnivora: Felidae) and their prey in Manu National Park

Article

Full-text available

Sep 2022

Protected areas, such as the 17,000 km² Manu National Park in Peru, are important for vulnerable species such as the jaguar, and population studies are needed to understand their conservation status. We did a short-term study using 136 paired camera traps stations deployed in three blocks across an area of 820 km² in Manu National Park to estimate: the density and distribution of jaguars, evaluate the availability and distribution of key prey (eight mammals and a bird), and investigate the use of space by predators, using occupancy models that considered environmental variables, prey availability, and competitors. Most prey species had an occupancy (psi) greater than 0.70, without clear patterns in the use of space. The use of space was intensive for ocelot (psi = 0.83, ES = 0.08) and jaguar (psi = 0.67, ES = 0.33), and less intensive for puma (psi = 0.25, SE = 0.07), yet without clear patterns related to the environmental variables we evaluated, the availability of prey and the presence of competitors. We estimate a jaguar density of 2 (ES=0.92; 95% CI =0.8-4.7) to 2.5 (ES=1.07, 95% CI = 1.1-5.6) ind/100 km², corresponding to a population of 193-241 jaguars for the lowlands of Manu. We conclude that jaguars are apparently abundant, both large carnivores and their prey can be found throughout the lowlands of the park, and their presence is not affected by spatial variations in habitat and human pressures.

Explaining detection heterogeneity with finite mixture and non-Euclidean movement in spatially explicit capture-recapture models

Article

Full-text available

Jun 2022

Landscape structure affects animal movement. Differences between landscapes may induce heterogeneity in home range size and movement rates among individuals within a population. These types of heterogeneity can cause bias when estimating population size or density and are seldom considered during analyses. Individual heterogeneity, attributable to unknown or unobserved covariates, is often modelled using latent mixture distributions, but these are demanding of data, and abundance estimates are sensitive to the parameters of the mixture distribution. A recent extension of spatially explicit capture-recapture models allows landscape structure to be modelled explicitly by incorporating landscape connectivity using non-Euclidean least-cost paths, improving inference, especially in highly structured (riparian & mountainous) landscapes. Our objective was to investigate whether these novel models could improve inference about black bear ( Ursus americanus ) density. We fit spatially explicit capture-recapture models with standard and complex structures to black bear data from 51 separate study areas. We found that non-Euclidean models were supported in over half of our study areas. Associated density estimates were higher and less precise than those from simple models and only slightly more precise than those from finite mixture models. Estimates were sensitive to the scale (pixel resolution) at which least-cost paths were calculated, but there was no consistent pattern across covariates or resolutions. Our results indicate that negative bias associated with ignoring heterogeneity is potentially severe. However, the most popular method for dealing with this heterogeneity (finite mixtures) yielded potentially unreliable point estimates of abundance that may not be comparable across surveys, even in data sets with 136–350 total detections, 3–5 detections per individual, 97–283 recaptures, and 80–254 spatial recaptures. In these same study areas with high sample sizes, we expected that landscape features would not severely constrain animal movements and modelling non-Euclidian distance would not consistently improve inference. Our results suggest caution in applying non-Euclidean SCR models when there is no clear landscape covariate that is known to strongly influence the movement of the focal species, and in applying finite mixture models except when abundant data are available.

Dinámicas productivas en torno al cambio de uso del suelo y sus repercusiones en la Reserva de Biósfera Maya (RBM) en Petén, Guatemala

Book

Full-text available

Dec 2021

Este documento busca aportar información socio ambiental que permita contribuir a comprender el papel cambiante de los bosques en la historia reciente de Petén. Analiza las dinámicas de cambio de uso de suelo que muestran diferencias a nivel de los espacios de la región, especialmente durante los últimos 20 años que lleva establecida la Reserva de Biósfera Maya (RBM) en el Departamento de Petén, Guatemala. Tiene como objetivo comprender los factores que han incidido en las dinámicas diferenciadas de uso de suelo en Petén, enfocándose en analizar los principales cambios económicoproductivos que implican trayectorias diferentes de uso de la tierra , así como sus implicaciones para la gestión de los recursos naturales a nivel de la RBM. Partiendo de una combinación de métodos cualitativos y cuantitativos y análisis de información geográfica busca aportar datos e información a los diversos procesos sobre la toma de decisiones en materia de recursos naturales. Los resultados apuntan a cambios en las trayectorias de política que tienen impactos en la percepción de los bosques, el uso de la tierra y la relación entre las poblaciones locales y los recursos naturales.

Conclusions: Trusting and Sustainable Development

Chapter

Dec 2021

Margit Ystanes

This chapter synthesises the main arguments of the book and outlines some of their implications for achieving sustainable development. A central argument presented is that the present ethnography and analysis constitutes a counterargument to the widespread ideas that societal trust is low in Latin American societies because it is concentrated within kinship and clientelist relationships. Rather than this being the case, trusting has a precarious foundation in the Ladino lifeworld, both in the private and public domains. As people create closures around themselves to ward off the social injustices emerging from the colonial past and a violent, unequal present, actors working towards a more sustainable future could promote societal trust by working to undo these injustices. With regard to the stewardship of Maya archaeological sites, this also includes a decolonialisation of archaeological and historical knowledge.

The Forestry Process

Chapter

Dec 2021

Margit Ystanes

This chapter outlines the forestry concession system. This approach to conservation and development was introduced into the Maya Biosphere Reserve in the years following its establishment in 1990, and those involved in it refer to it as ‘the forestry process’. While the creation of the reserve as well as the concession system was controversial and met initial resistance for complex reasons, the forestry concessions are now well consolidated and internationally recognised for their conservation work. This chapter also explores different aspects of how forestry concessionaires experience living in the forest, forms of work integrated in the concession system, and connects the forest to the Ladino lifeworld.

Selvas en Misiones

Chapter

Full-text available

Oct 2021

Los bosques nativos brindan una amplia variedad de bienes y servicios ecosistémicos, otorgando oportunidades sociales y económicas, por lo que es necesario desarrollar una silvicultura integrada que responda a tales fines, por ejemplo, producción maderera, no maderera y conservación. En este Capítulo se presentan propuestas y estrategias para mejorar la implementación del manejo sostenible de los bosques nativos en la Argentina, basadas en el actual desarrollo del conocimiento de la silvicultura, tomando como base al manejo adaptativo, el agregado de valor a los productos obtenidos del bosque, y la necesidad de la restauración de los bosques nativos para recuperar potencialidades perdidas. Asimismo, se plantean los principales desafíos para los próximos años como el manejo multipropósito a distintas escalas del paisaje, la adaptación del manejo silvícola a las modificaciones del clima, y la implementación de indicadores y sistemas de monitoreo. Por último, se presenta en forma sintética las principales recomendaciones sobre la silvicultura y manejo del bosque nativo para los tomadores de decisiones de las diferentes regiones forestales del país.

Is it an omnivore's world? A comment on dietary traits in multispecies hierarchical models

Article

Aug 2021
BIOL CONSERV

Protected areas remain at the forefront of conservation action plans and are a critical management approach to sustain and restore global biodiversity. In their recent paper, Ferreira et al. (2020) present a compelling case that strict protected areas are essential for the conservation of large and threatened Neotropical mammals in the Brazilian Cerrado. The authors used a large-scale camera trap network across two levels of protected areas to make strong inferences with results that are robust and actionable for conservation moving forward. Upon reviewing species-specific responses to habitat modification and fragmentation versus strict protected areas, one additional pattern appears to prevail. The three species that were most associated with less strictly protected areas were all omnivores (e.g., hoary fox [Lycalopex vetulus], crab-eating fox [Cerdocyon thous], and hog-nosed skunk [Conepatus semistriatus]). This raises the additional question: are anthropogenic changes driving us towards an omnivore's world?

Estimating jaguar (Panthera onca) density in a preserved coastal area of French Guiana

Article

Full-text available

May 2017

Knowledge of the jaguar population is needed in French Guiana that faces an increase of human-jaguar conflicts. We carried out a camera trap survey to assess jaguar local density and home range size in a preserved coastal area of French Guiana. We ran spatially explicit capture recapture (SECR) models. In our model, the scale parameter σ, that is linked to the home range size, was larger for males (σ=3.87±0.59 SE km) than for females (σ=2.33±0.30 SE km). The assessed jaguar density was 3.22±0.87 SE ind. 100 km⁻², which should be considered as an optimal density in a French Guiana coastal area.

Logging and indigenous hunting impacts on persistence of large Neotropical animals

Article

Full-text available

May 2017
BIOTROPICA

Areas allocated for industrial logging and community-owned forests account for over 50% of all remaining tropical forests. Landscape-scale conservation strategies that include these forests are expected to have substantial benefits for biodiversity, especially for large mammals and birds that require extensive habitat but that are susceptible to extirpation due to synergies between logging and hunting. In addition, their responses to logging alone are poorly understood due to their cryptic behavior and low densities. In this study, we assessed the effects of logging and hunting on detection and occupancy rates of large vertebrates in a multiple-use forest on the Guiana Shield. Our study site was certified as being responsibly managed for timber production and indigenous communities are legally guaranteed use-rights to the forest. We coupled camera-trap data for wildlife detection with a spatially explicit dataset on indigenous hunting. A multi-species occupancy model found a weak positive effect of logging on occupancy and detection rates, while hunting had a weak negative effect. Model predictions of species richness were also higher in logged forest sites compared to unlogged forest sites. Density estimates for jaguars and ocelots in our multiple-use area were similar to estimates reported for fully protected areas. Involvement of local communities in forest management, control of forest access, and nesting production forests in a landscape that includes protected areas seemed important for these positive biodiversity outcomes. The maintenance of vertebrate species bodes well for both biodiversity and the humans that depend on multiple-use forests.

Space Use and Movement of a Neotropical Top Predator: The Endangered Jaguar

Article

Full-text available

Dec 2016
PLOS ONE

Accurately estimating home range and understanding movement behavior can provide important information on ecological processes. Advances in data collection and analysis have improved our ability to estimate home range and movement parameters, both of which have the potential to impact species conservation. Fitting continuous-time movement model to data and incorporating the autocorrelated kernel density estimator (AKDE), we investigated range residency of forty-four jaguars fit with GPS collars across five biomes in Brazil and Argentina. We assessed home range and movement parameters of range resident animals and compared AKDE estimates with kernel density estimates (KDE). We accounted for differential space use and movement among individuals, sex, region, and habitat quality. Thirty-three (80%) of collared jaguars were range resident. Home range estimates using AKDE were 1.02 to 4.80 times larger than KDE estimates that did not consider autocorrela-tion. Males exhibited larger home ranges, more directional movement paths, and a trend towards larger distances traveled per day. Jaguars with the largest home ranges occupied the Atlantic Forest, a biome with high levels of deforestation and high human population density. Our results fill a gap in the knowledge of the species' ecology with an aim towards PLOS ONE |

Density and population structure of the jaguar (Panthera onca) in a protected area of Los Llanos, Venezuela, from 1 year of camera trap monitoring

Article

Full-text available

Nov 2016

Density is crucial for understanding large carnivore ecology and conservation, but estimating it has proven methodologically difficult. We conducted 1 year of camera trapping to estimate jaguar (Panthera onca) density and population structure in the Los Llanos region of Venezuela on the Hato Piñero ranch, where hunting is prohibited and livestock are excluded from half of ranch lands. We identified 42 different jaguars and determined their sex, age class, and reproductive status. We estimated adult jaguar densities with spatial capture-recapture models, using sex/reproductive state and session as covariates. Models without temporal variation received more support than models that allowed variation between sessions. Males, reproductive females, and nonreproductive females differed in their density, baseline detectability, and movement. The best estimate of total adult jaguar population density was 4.44 individuals/100 km². Based on reproductive female density and mean number of offspring per female, we estimated cub density at 3.23 individuals/100 km² and an overall density of 7.67 jaguars/100 km². Estimated jaguar population structure was 21% males, 11% nonreproductive females, 26% reproductive females, and 42% cubs. We conclude that extending the sampling period to 1 year increases the detectability of females and cubs and makes density estimates more robust as compared to the more common short studies. Our results demonstrate that the Venezuelan Llanos represent important jaguar habitat, and further, they emphasize the importance of protected areas and hunting restrictions for carnivore conservation.

Impact of Forest Management on Species Richness: Global Meta Analysis and Economic Trade-Offs

Article

Full-text available

Apr 2016

Abhishek Chaudhary

Forests managed for timber have an important role to play in conserving global biodiversity. We evaluated the most common timber production systems worldwide in terms of their impact on local species richness by conducting a categorical meta-analysis. We reviewed 287 published studies containing 1008 comparisons of species richness in managed and unmanaged forests and derived management, taxon, and continent specific effect sizes. We show that in terms of local species richness loss, forest management types can be ranked, from best to worse, as follows: selection and retention systems, reduced impact logging, conventional selective logging, clear-cutting, agroforestry, timber plantations, fuelwood plantations. Next, we calculated the economic profitability in terms of the net present value of timber harvesting from 10 hypothetical wood-producing Forest Management Units (FMU) from around the globe. The ranking of management types is altered when the species loss per unit profit generated from the FMU is considered. This is due to differences in yield, timber species prices, rotation cycle length and production costs. We thus conclude that it would be erroneous to dismiss or prioritize timber production regimes, based solely on their ranking of alpha diversity impacts.

Natural Forest Management as a Conservation Tool in the Tropics: Divergent Views on Possibilities and Alternatives

Article

Full-text available

Jan 1996

A round table discussion was convened to explore divergent views on the potential for natural forest management (NFM) for timber to contribute to wide-scale maintenance of forest cover and biological diversity in tropical forests The general argument for NFM for timber is that, by conferring relatively more economic value on forests than alternative forest uses, NFM for timber is a necessary, though imperfect, means by which extensive areas of forest cover and a large measure of their biological diversity would be maintained outside nature reserves. The discussion centred on five topics: the biological-diversity-related benefits and drawbacks of instituting NFM for timber, the biological and economic constraints on successful NFM for timber, the alternatives to NFM for timber, and the relative merits of community versus industrial concessions as mechanisms by which to institute NFM for limber. Both proponents and critics of NFM for timber should recognise that, first, NFM for timber can be carried out in ways that mitigate the negative effects on biological diversity and, second, there is a common set of conditions necessary to maintain forest cover for any use, including NFM for timber or nature reserves.

Spatiotemporal hierarchical modelling of species richness and occupancy using camera trap data

Article

Full-text available

Feb 2015
J APPL ECOL

Over the last two decades, a large number of camera trap surveys have been carried out around the world and camera traps have been proposed as an ideal tool for inventorying and monitoring medium to large‐sized terrestrial vertebrates. However, few studies have analysed camera trap data at the community level. We developed a multi‐session multi‐species occupancy model that allows us to obtain estimates for species richness and occupancy combining data from multiple camera trap surveys (sessions). By estimating species presence at the session‐level and modelling detection probability and occupancy for each species and sessions as nested random effects, we could improve parameter estimates for each session, especially for species with sparse data. We developed two variants of our model: one was a binary latent states model while the other used a Royle–Nichols formulation for the relationship between detection probability and abundance. We applied both models to data from eight camera trap surveys from south‐eastern Peru including six study sites, 263 camera stations and 17 423 camera days. Sites covered protected areas, a logging concession and Brazil nut concessions. We included habitat ( terra firme vs. floodplain) as a covariate for occupancy and trail vs. off‐trail as a covariate for detection. Among‐camera heterogeneity was a serious problem for our data and the Royle–Nichols variant of our model had a much better fit than the binary‐state variant. Both models resulted in similar species richness estimates showing that most of the sites contained intact large mammal communities. Detection probabilities and occupancy values were more variable across species than across sessions within species. Three species showed a habitat preference and four species showed preference or avoidance of trails. Synthesis and applications . Our multi‐session multi‐species occupancy model provides improved estimates for species richness and occupancy for a large data set. Our model is ideally suited for integrating large numbers of camera trap data sets to investigate regional and/or temporal patterns in the distribution and composition of mammal communities in relation to natural or anthropogenic factors or to monitor mammal communities over time.

Camera trap photographic rates on roads vs. off roads: Location does matter

Article

Full-text available

Jun 2014

We present the results of a camera trap survey conducted in 2008 in the Atlantic Forest of Iguazú National Park, Misiones, Argentina, testing whether placing camera traps on dirt roads/trails or in off-road locations produce important biases in the recorded species. Seven pairs of camera trap stations were active for 26.6 ± 8.9 days; for each pair, one station was located on a narrow unpaved road and the other about 50 m from the road. We used the first order Jackknife estimator to compare species richness between on-road vs. off-road locations. We used records from another camera trap survey conducted at Iguazú National Park in 2006-2007 to assess whether species with a high Road-use Index (ratio of photographs of animals walking along roads to photographs of animals crossing the roads) had a higher ratio of records on roads/off road stations in the 2008 survey. Multivariate ANOVA based on dissimilarities (ADONIS) was used to compare mammal assemblages recorded at stations located on roads vs. off roads. We obtained 228 independent records of 15 species of medium-large sized terrestrial mammals. Stations located on roads had a higher recording rate (1.06, SD = 0.57 vs. 0.24, SD = 0.13 records per day) and recorded more species than off-road stations (15 vs. 10 recorded species; 19.3, SE = 2.8 vs. 14.3, SE = 2.8 species estimated with the 1st order Jackknife model). Species differ in their relative probabilities of being recorded on roads vs. off roads, something that can be predicted with the Road-use Index. The ADONIS indicated that the mammal assemblage surveyed on roads was statistically dissimilar to that surveyed off roads, a result that can be explained by the differential tendency of the species to use roads and trails.

Improved timber harvest techniques maintain biodiversity in tropical forests

Article

Full-text available

Dec 2014
CURR BIOL

Tropical forests are selectively logged at 20 times the rate at which they are cleared, and at least a fifth have already been disturbed in this way [1]. In a recent pan-tropical assessment, Burivalova et al.[2] demonstrate the importance of logging intensity as a driver of biodiversity decline in timber estates. Their analyses reveal that species richness of some taxa could decline by 50% at harvest intensities of 38 m(3) ha(-1). However, they did not consider the extraction techniques that lead to these intensities. Here, we conduct a complementary meta-analysis of assemblage responses to differing logging practices: conventional logging and reduced-impact logging. We show that biodiversity impacts are markedly less severe in forests that utilise reduced-impact logging, compared to those using conventional methods. While supporting the initial findings of Burivalova et al.[2], we go on to demonstrate that best practice forestry techniques curtail the effects of timber extraction regardless of intensity. Therefore, harvest intensities are not always indicative of actual disturbance levels resulting from logging. Accordingly, forest managers and conservationists should advocate practices that offer reduced collateral damage through best practice extraction methods, such as those used in reduced-impact logging. Large-scale implementation of this approach would lead to improved conservation values in the 4 million km(2) of tropical forests that are earmarked for timber extraction [3]. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modeling non-Euclidean movement and landscape connectivity in highly structured ecological networks

Article

Full-text available

Feb 2015
Methods Ecol. Evol.

Movement is influenced by landscape structure, configuration and geometry, but measuring distance as perceived by animals poses technical and logistical challenges. Instead, movement is typically measured using Euclidean distance, irrespective of location or landscape structure, or is based on arbitrary cost surfaces. A recently proposed extension of spatial capture‐recapture ( SCR ) models resolves this issue using spatial encounter histories of individuals to calculate least‐cost paths (ecological distance: Ecology , 94 , 2013, 287) thereby relaxing the Euclidean assumption. We evaluate the consequences of not accounting for movement heterogeneity when estimating abundance in highly structured landscapes, and demonstrate the value of this approach for estimating biologically realistic space‐use patterns and landscape connectivity. We simulated SCR data in a riparian habitat network, using the ecological distance model under a range of scenarios where space‐use in and around the landscape was increasingly associated with water (i.e. increasingly less Euclidean). To assess the influence of miscalculating distance on estimates of population size, we compared the results from the ecological and Euclidean distance based models. We then demonstrate that the ecological distance model can be used to estimate home range geometry when space use is not symmetrical. Finally, we provide a method for calculating landscape connectivity based on modelled species‐landscape interactions generated from capture‐recapture data. Using ecological distance always produced unbiased estimates of abundance. Explicitly modelling the strength of the species‐landscape interaction provided a direct measure of landscape connectivity and better characterised true home range geometry. Abundance under the Euclidean distance model was increasingly (negatively) biased as space use was more strongly associated with water and, because home ranges are assumed to be symmetrical, produced poor characterisations of home range geometry and no information about landscape connectivity. The ecological distance SCR model uses spatially indexed capture‐recapture data to estimate how activity patterns are influenced by landscape structure. As well as reducing bias in estimates of abundance, this approach provides biologically realistic representations of home range geometry, and direct information about species‐landscape interactions. The incorporation of both structural (landscape) and functional (movement) components of connectivity provides a direct measure of species‐specific landscape connectivity.

Effects of logging on tropical forest ungulates

Chapter

Full-text available

Jan 2001

The information on the ecology of most forest dwelling, terrestrial mammals is sparse, often anecdotal, widely scattered in the literature, and supported by very few long-term studies. This chapter focuses on ungulates—a group of medium to large-sized terrestrial mammals, which includes elephants, odd-toed hoofed mammals (such as rhinos and tapirs), and even-toed hoofed mammals (such as cattle and antelopes). These mammals are: — Important sources of subsistence animal protein for many peoples — Central to the wild meat (bushmeat) trade in many parts of the world — A source of opportunity for forest ecotourism — Integral parts of forest ecosystem processes (e.g., seed dispersal) — Major determinants of forest vegetation structure and composition

Determination of tropical deforestation rates and related carbon losses from 1990 to 2010

Article

Full-text available

Apr 2014
GLOBAL CHANGE BIOL

We estimate changes in forest cover (deforestation and forest regrowth) in the tropics for the two last decades (1990-2000 and 2000-2010) based on a sample of 4,000 units of 10km×10km size. Forest cover is interpreted from satellite imagery at 30m×30m resolution. Forest cover changes are then combined with pan-tropical biomass maps to estimate carbon losses. We show that there was a gross loss of tropical forests of 8.0 million ha y−1 in the 1990s and 7.6 million ha y−1 in the 2000s (0.49% annual rate), with no statistically significant difference. Humid forests account for 64% of the total forest cover in 2010 and 54% of the net forest loss during second study decade. Losses of forest cover and other wooded land cover result in estimates of carbon losses which are similar for 1990s and 2000s at 887 MtC y−1 (range: 646 – 1238) and 880 MtC y−1 (range: 602 – 1237) respectively, with humid regions contributing two thirds. The estimates of forest area changes have small statistical standard errors due to large sample size. We also reduce uncertainties of previous estimates of carbon losses and removals. Our estimates of forest area change are significantly lower as compared to national survey data. We reconcile recent low estimates of carbon emissions from tropical deforestation for early 2000s and show that carbon loss rates did not change between the two last decades. Carbon losses from deforestation represent circa 10% of Carbon emissions from fossil fuel combustion and cement production during the last decade (2000-2010). Our estimates of annual removals of carbon from forest regrowth at 115 MtC y−1 (range: 61-168) and 97 MtC y−1 (53-141) for the 1990s and 2000s respectively are five to fifteen times lower than earlier published estimates.This article is protected by copyright. All rights reserved.

Agricultural expansion and its impacts on tropical nature

Article

Full-text available

Dec 2013
TRENDS ECOL EVOL

The human population is projected to reach 11 billion this century, with the greatest increases in tropical developing nations. This growth, in concert with rising per-capita consumption, will require large increases in food and biofuel production. How will these megatrends affect tropical terrestrial and aquatic ecosystems and biodiversity? We foresee (i) major expansion and intensification of tropical agriculture, especially in Sub-Saharan Africa and South America; (ii) continuing rapid loss and alteration of tropical old-growth forests, woodlands, and semi-arid environments; (iii) a pivotal role for new roadways in determining the spatial extent of agriculture; and (iv) intensified conflicts between food production and nature conservation. Key priorities are to improve technologies and policies that promote more ecologically efficient food production while optimizing the allocation of lands to conservation and agriculture.

High-Resolution Global Maps of 21st-Century Forest Cover Change

Article

Full-text available

Nov 2013
SCIENCE

Forests in Flux Forests worldwide are in a state of flux, with accelerating losses in some regions and gains in others. Hansen et al. (p. 850 ) examined global Landsat data at a 30-meter spatial resolution to characterize forest extent, loss, and gain from 2000 to 2012. Globally, 2.3 million square kilometers of forest were lost during the 12-year study period and 0.8 million square kilometers of new forest were gained. The tropics exhibited both the greatest losses and the greatest gains (through regrowth and plantation), with losses outstripping gains.

Quantifying the biodiversity value of repeatedly logged rainforests: gradient and comparative approaches from Borneo

Article

Full-text available

Jan 2013
ADV ECOL RES

Monitoring the Status and Trends of Tropical Forest Terrestrial Vertebrate Communities from Camera Trap Data: A Tool for Conservation

Article

Full-text available

Sep 2013
PLOS ONE

Reducing the loss of biodiversity is key to ensure the future well being of the planet. Indicators to measure the state of biodiversity should come from primary data that are collected using consistent field methods across several sites, longitudinal, and derived using sound statistical methods that correct for observation/detection bias. In this paper we analyze camera trap data collected between 2008 and 2012 at a site in Costa Rica (Volcan Barva transect) as part of an ongoing tropical forest global monitoring network (Tropical Ecology Assessment and Monitoring Network). We estimated occupancy dynamics for 13 species of mammals, using a hierarchical modeling approach. We calculated detection-corrected species richness and the Wildlife Picture Index, a promising new indicator derived from camera trap data that measures changes in biodiversity from the occupancy estimates of individual species. Our results show that 3 out of 13 species showed significant declines in occupancy over 5 years (lowland paca, Central American agouti, nine-banded armadillo). We hypothesize that hunting, competition and/or increased predation for paca and agouti might explain these patterns. Species richness and the Wildlife Picture Index are relatively stable at the site, but small herbivores that are hunted showed a decline in diversity of about 25%. We demonstrate the usefulness of longitudinal camera trap deployments coupled with modern statistical methods and advocate for the use of this approach in monitoring and developing global and national indicators for biodiversity change.

Reconciling Forest Conservation and Logging in Indonesian Borneo

Article

Full-text available

Aug 2013
PLOS ONE

Combining protected areas with natural forest timber concessions may sustain larger forest landscapes than is possible via protected areas alone. However, the role of timber concessions in maintaining natural forest remains poorly characterized. An estimated 57% (303,525 km2) of Kalimantan's land area (532,100 km2) was covered by natural forest in 2000. About 14,212 km2 (4.7%) had been cleared by 2010. Forests in oil palm concessions had been reduced by 5,600 km2 (14.1%), while the figures for timber concessions are 1,336 km2 (1.5%), and for protected forests are 1,122 km2 (1.2%). These deforestation rates explain little about the relative performance of the different land use categories under equivalent conversion risks due to the confounding effects of location. An estimated 25% of lands allocated for timber harvesting in 2000 had their status changed to industrial plantation concessions in 2010. Based on a sample of 3,391 forest plots (1×1 km; 100 ha), and matching statistical analyses, 2000–2010 deforestation was on average 17.6 ha lower (95% C.I.: −22.3 ha–−12.9 ha) in timber concession plots than in oil palm concession plots. When location effects were accounted for, deforestation rates in timber concessions and protected areas were not significantly different (Mean difference: 0.35 ha; 95% C.I.: −0.002 ha–0.7 ha). Natural forest timber concessions in Kalimantan had similar ability as protected areas to maintain forest cover during 2000–2010, provided the former were not reclassified to industrial plantation concessions. Our study indicates the desirability of the Government of Indonesia designating its natural forest timber concessions as protected areas under the IUCN Protected Area Category VI to protect them from reclassification.

Improving density estimates for elusive carnivores: Accounting for sex-specific detection and movements using spatial capture–recapture models for jaguars in central Brazil

Article

Full-text available

Mar 2011
BIOL CONSERV

Owing to habitat conversion and conflict with humans, many carnivores are of conservation concern. Because of their elusive nature, camera trapping is a standard tool for studying carnivores. In many vertebrates, sex-specific differences in movements – and therefore detection by cameras – are likely. We used camera trapping data and spatially explicit sex-specific capture–recapture models to estimate jaguar density in Emas National Park in the central Brazilian Cerrado grassland, an ecological hotspot of international importance. Our spatially explicit model considered differences in movements and trap encounter rate between genders and the location of camera traps (on/off road). We compared results with estimates from a sex-specific non-spatial capture–recapture model. The spatial model estimated a density of 0.29 jaguars 100km−2 and showed that males moved larger distances and had higher trap encounter rates than females. Encounter rates with off-road traps were one tenth of those for on-road traps. In the non-spatial model, males had a higher capture probability than females; density was estimated at 0.62 individuals 100km−2. The non-spatial model likely overestimated density because it did not adequately account for animal movements. The spatial model probably underestimated density because it assumed a uniform distribution of jaguars within and outside the reserve. Overall, the spatial model is preferable because it explicitly considers animal movements and allows incorporating site-specific and individual covariates. With both methods, jaguar density was lower than reported from most other study sites. For rare species such as grassland jaguars, spatially explicit capture–recapture models present an important advance for informed conservation planning.

Amazonian Small Mammal Abundances in Relation to Habitat Structure and Resource Abundance

Article

Full-text available

Aug 2006

Previous studies in tropical rain forests suggest that most small mammal species reach their highest densities in disturbed habitats; however, only a few sites have been examined. Consequently, habitat and resource use for many species is poorly understood. This is especially true in the Amazon Basin, where no studies of microhabitat associations of small mammals have been undertaken. We studied relationships with habitat variables and resource abundances for 5 species of marsupials and 9 species of rodents at a site in southeastern Amazonia. Small mammals were sampled with traps placed both on the ground and in the understory. Eight habitat variables were measured to quantify habitat structure. Measures of insect biomass were collected by the use of sticky traps, and fruit abundance was quantified. Patterns of habitat use were examined using logistic regression, multiple regression, and ordinations. Many species showed increased abundances with habitat features indicative of edge-affected or disturbed habitats, showing negative relationships with understory openness, understory woody-stem density, tree density, and tree size; and positive relationships with number of vines per tree, mean log size, number of logs, and volume of downed wood. We obtained support for the hypothesis that the cause of this pattern is increased resource abundances in these areas, because both insect biomass and number of fruiting trees showed similar relationships. However, for many species, measures of resource abundance were not important once habitat features were entered into the models, indicating that the relationship to resources is an indirect one.

Comparison of density estimation methods for mammal populations with camera traps in the Kaa-Iya del Gran Chaco landscape

Article

Full-text available

Oct 2012

Sampling animal populations with camera traps has become increasingly popular over the past two decades, particularly for species that are cryptic, elusive, exist at low densities or range over large areas. The results have been widely used to estimate population size and density. We analyzed data from 13 camera trap surveys conducted at five sites across the Kaa-Iya landscape, Bolivian Chaco, for jaguar, puma, ocelot and lowland tapir. We compared two spatially explicit capture–recapture (SCR) software packages: secr, a likelihood-based approach, and SPACECAP, a Bayesian approach, both of which are implemented within the R environment and can be used to estimate animal density from photographic records of individual animals that simultaneously employ spatial information about the capture location relative to the sample location. As a non-spatial analy- sis, we used the program CAPTURE 2 to estimate abundance from the capture– recapture records of individuals identified through camera trap photos combined with an ad hoc estimation of the effective survey area to estimate density. SCR methods estimated jaguar population densities from 0.31 to 1.82 individuals per 100 km2 across the Kaa-Iya sites; puma from 0.36 to 7.99; ocelot from 1.67 to 51.7; and tapir from 7.38 to 42.9. Density estimates using either secr or SPACECAP were generally lower than the estimates generated using the non-spatial method for all surveys and species; and density estimates usingSPACECAPwere generally lower than that using secr. We recommend using either secr or SPACECAP because the spatially explicit methods are not biased by an informal estimation of an effective survey area. Although SPACECAP and secr are less sensitive than non-spatial methods to the size of the grid used for sampling, we recommend grid sizes several times larger than the average home range (known or estimated) of the target species.

Forest Certification in Guatemala

Article

Full-text available

Jan 2006

The forest certification process in Guatemala has largely been confined to the forest concessions in the Maya Biosphere Reserve (MBR), representing 95 percent of the country's certified forest area. Forest certification in Guatemala is unique in that certification in accordance with the scheme of the Forest Stewardship Council (FSC) is mandatory in order for both communities and industrial groups to obtain and maintain forest concessions in the MBR. Unlike other countries where forest certification has almost exclusively been advanced in a joint effort between non- governmental organizations, development projects and the private sector, the case of Guatemala shows the important role government agencies can play as agents backing the process. Despite initial resistance, the National Council for Protected Areas (CONAP), as the state agency in charge of the Maya Biosphere Reserve in the Petén region of northern Guatemala, permitted forest management in the MBR provided that it was subject to FSC certification. Sixteen forest management units covering close to half a million hectares of broadleaved forests have since been certified, including 10 community concessions, four cooperatives or municipal ejidos and two industrial concessions. In addition, two forest plantations outside the MBR have been certified. Notwithstanding the considerable progress towards sustainable forest management in the MBR, economic benefits as returns on certification investments have generally not lived up to expectations. Moreover, forest certification has yet to gain momentum outside the Maya Biosphere Reserve where the process is voluntary. Increasing the benefits of certification and expanding its coverage would require a concerted effort between the various stakeholders involved, thorough cost-benefit analysis in each individual case, and the development of integrated supply chains of certified forest products. Toward this end, we suggest creating learning alliances between key actors in the certification process, such as managers from certified management units and processing plants, non-governmental and governmental organizations, certification and accreditation bodies, donor agencies, research institutions, and business development service providers.

Spatial capture–recapture for jointly estimating population density and landscape connectivity

Article

Full-text available

Feb 2013

Population size and landscape connectivity are key determinants of population viability, yet no methods exist for simultaneously estimating density and connectivity parameters. Recently developed spatial capture--recapture (SCR) models provide a framework for estimating density of animal populations but thus far have not been used to study connectivity. Rather, all applications of SCR models have used encounter probability models based on the Euclidean distance between traps and animal activity centers, which implies that home ranges are stationary, symmetric, and unaffected by landscape structure. In this paper we devise encounter probability models based on "ecological distance," i.e., the least-cost path between traps and activity centers, which is a function of both Euclidean distance and animal movement behavior in resistant landscapes. We integrate least-cost path models into a likelihood-based estimation scheme for spatial capture-recapture models in order to estimate population density and parameters of the least-cost encounter probability model. Therefore, it is possible to make explicit inferences about animal density, distribution, and landscape connectivity as it relates to animal movement from standard capture-recapture data. Furthermore, a simulation study demonstrated that ignoring landscape connectivity can result in negatively biased density estimators under the naive SCR model.

Wildlife Harvest in Logged Tropical Forests

Article

Full-text available

Apr 1999
SCIENCE

Commercial logging, by opening up remote tropical forest areas, stimulating a commercial trade, and bringing in people from other areas, has hugely increased the harvest of wildlife. This loss of wildlife threatens the ability of forest-dwelling people to feed themselves, the survival of harvested species, and the sustainability of tropical forestry itself. As commercial forestry has created the conditions for the increased wildlife harvest, regulatory mechanisms should focus on forestry operations. While progress has been slight to date, there is some openness within the industry to the idea of sustaining all elements of the rain forest ecosystem, including wildlife, when forests are logged.

Short Communication The importance of selectively logged forests for tiger Panthera tigris conservation: a population density estimate in Peninsular Malaysia

Article

Full-text available

Jan 2009
ORYX

To obtain information on density of tiger Panthera tigris in selectively logged forest, a 9-month camera-trapping survey was conducted over elevations of 190–850 m in lowland and hill/upper dipterocarp and lower montane forests in Gunung Basor Forest Reserve, Peninsular Malaysia. Capture-recapture sampling methods were used to estimate tiger population density in the Reserve. The number of individual tigers captured was six. Using the Mh jackknife estimator the average capture probability per sampling occasion was 0.28 and the corresponding estimate of population size 8 ± SE 1.89. The overall probability of photo-capturing a tiger present in the sampled area was 0.75. Using an approach based on distances between photo-captures, a buffer width of 3.22 km and an effectively sampled area of 308 km2 was estimated. This resulted in a density estimate of 2.59 ± SE 0.71 adult tigers per 100 km2. The results indicate that selectively logged forests such as Gunung Basor Forest Reserve have the potential to accommodate a high density of tigers. Decision makers and conservation planners should not therefore perceive selectively logged forests to have limited conservation value. Further research on the ecology of tigers and their prey in selectively logged forests is urgently needed. Such research would enable conservationists to recommend tiger-friendly management guidelines for sustainable forest management and thereby significantly contribute to tiger conservation in Malaysia.

Does Forest Certification Conserve Biodiversity?

Article

Full-text available

Apr 2003
ORYX

Raymond Edward Gullison

Forest certification provides a means by which producers who meet stringent sustainable forestry standards can identify their products in the marketplace, allowing them to potentially receive greater market access and higher prices for their products. An examination of the ways in which certification may contribute to biodiversity conservation leads to the following conclusions: 1) the process of Forest Stewardship Council (FSC)-certification generates improvements to management with respect to the value of managed forests for biodiversity. 2) Current incentives are not sufficient to attract the majority of producers to seek certification, particularly in tropical countries where the costs of improving management to meet FSC guidelines are significantly greater than any market benefits they may receive; available incentives are even less capable of convincing forest owners to retain forest cover and produce certified timber on a sustainable basis, rather than deforesting their lands for timber and agriculture. 3) At present, current volumes of certified forest products are insufficient to reduce demand to log high conservation value forests. If FSC certification is to make greater inroads, particularly in tropical countries, significant investments will be needed both to increase the benefits and reduce the costs of certification. Conservation investors will need to carefully consider the biodiversity benefits that will be generated from such investments, versus the benefits generated from investing in more traditional approaches to biodiversity conservation.

An evaluation of camera traps for inventorying large- and medium-sized terrestrial rainforest mammals

Article

Full-text available

Jun 2008
ANIM CONSERV

Mammal inventories in tropical forests are often difficult to carry out, and many elusive species are missed or only reported from interviews with local people. Camera traps offer a new tool for conducting inventories of large- and medium-sized terrestrial mammals. We evaluated the efficiency of camera traps based on data from two surveys carried out at a single site during 2 consecutive years. The survey efforts were 1440 and 2340 camera days, and 75 and 86% of the 28 large- and medium-sized terrestrial mammal species known to occur at the site were recorded. Capture frequencies for different species were highly correlated between the surveys, and the capture probability for animals that passed in front of the cameras decreased with decreasing size of the species. Camera spacing and total survey area had little influence on the number of species recorded, with survey effort being the main factor determining the number of recorded species. Using a model we demonstrated the exponential increase in survey effort required to record the most elusive species. We evaluated the performance of different species richness estimators on this dataset and found the Jackknife estimators generally to perform best. We give recommendations on how to increase efficiency of camera trap surveys exclusively targeted at species inventories.

The food habits of jaguars and pumas across a gradient of human disturbance

Article

Full-text available

Mar 2010
J ZOOL

Jaguars Panthera onca coexist with pumas Puma concolor across their entire range. In areas where they occur together their coexistence may be facilitated by differences in diet. This study compared food habits of jaguars and pumas in Belize, Central America, across a protected lowland rainforest and the neighbouring human-influenced landscape. Diets were determined from 362 jaguar scats and 135 puma scats, identified by genetic analysis. In the protected forest, dietary breadths were low for jaguars and pumas and showed little overlap. In this habitat each relied heavily on a single medium-sized (5–10 kg) prey species: armadillos Dasypus novemcinctus for jaguars, and pacas Agouti paca for pumas. Both cats also took larger prey (>10 kg), mainly white-lipped peccaries Tayassu pecari by jaguars and red brocket deer Mazama americana by pumas. In unprotected fragmented lands, jaguar scats rarely contained large wild prey species; rather, a diet of relatively small wild prey was supplemented with larger domestic species. Pumas did not take domestic species and were scarce outside the protected forest, possibly indicating competition with humans for pacas and deer, which are also prized game species in the region. This study is the largest analysis to date of sympatric jaguar and puma diets in both forest and farmland. We suggest that jaguar predation on cattle may be reduced by ensuring that game hunting is sustainable and potentially by augmenting forests within the human matrix with large wild ungulates. The supplementation could benefit both of the cat species, and the local game hunting economy.

Comparative Feeding Ecology of Felids in a Neotropical Rain-Forest

Article

Full-text available

Apr 1987

Louise Emmons

Diet and habitat use of jaguar, puma, and ocelot, and populations of their mammalian prey, were studied in an undisturbed rainforest in southeastern Peru. Analysis of scats (feces) showed terrestrial mammals to be the chief prey of all three felids, but reptiles and birds were also numerically important in the diets of ocelot and jaguar. Prey diversity is high and the cats evidently take any readily captured vertebrate. For major terrestrial mammal prey of felids, density, biomass, prey/predator ratios, and annual offtake from the study area are estimated. All three cat species seem to hunt by opportunistic encounter of prey. Most mammalian prey species were taken in about the ratios of occurrence, but peccaries were taken by jaguar more often than expected. Most prey of jaguar have a body weight of >1 kg, those of ocelot, 1 kg. Jaguar often used waterside habitats, where they captured caiman and river turtles. Puma did not use these habitats or resources, although the puma prey sample was too small for much inference. The possible effects of felids on study area prey populations are discussed. Large and small cats partition prey at the body weight region where prey switches from low to high reproductive rates.

The persistence and conservation of Borneo's mammals in lowland rain forests managed for timber: Observations, overviews and opportunities

Article

Full-text available

Feb 2007

Lowland rainforests on Borneo are being degraded and lost at an alarming rate. Studies on mammals report species responding in various ways to habitat changes that occur in commercial forestry concessions. Here we draw together information on the relationship between the ecological, evolutionary, and biogeographic characteristics of selected Bornean non-volant mammals, and their response to timber harvesting and related impacts. Only a minority of species show markedly reduced densities after timber harvesting. Nonetheless there are many grounds for concern as various processes can, and often do, reduce the viability of wildlife populations. Our review of what we know, and of current understanding, helps predict mammalian dynamics and subsequent mammal-induced ecosystem changes in logged forests. We identify groups of mammal species that, although largely unstudied, are unlikely to tolerate the impacts associated with timber harvesting. On a positive note we find and suggest many relatively simple and low-cost ways in which concession management practices might be modified so as to improve the value of managed forests for wildlife conservation. Improving forest management can play a vital role in maintaining the rich biodiversity of Borneo’s tropical rain forests.

Sustaining conservation values in selectively logged tropical forests: The attained and the attainable

Article

Full-text available

Aug 2012

Most tropical forests outside protected areas have been or will be selectively logged so it is essential to maximize the conservation values of partially harvested areas. Here we examine the extent to which these forests sustain timber production, retain species, and conserve carbon stocks. We then describe some improvements in tropical forestry and how their implementation can be promoted. A simple meta-analysis based on >100 publications revealed substantial variability but that: timber yields decline by about 46% after the first harvest but are subsequently sustained at that level; 76% of carbon is retained in once-logged forests; and, 85–100% of species of mammals, birds, invertebrates, and plants remain after logging. Timber stocks will not regain primary-forest levels within current harvest cycles, but yields increase if collateral damage is reduced and silvicultural treatments are applied. Given that selectively logged forests retain substantial biodiversity, carbon, and timber stocks, this “middle way” between deforestation and total protection deserves more attention from researchers, conservation organizations, and policy-makers. Improvements in forest management are now likely if synergies are enhanced among initiatives to retain forest carbon stocks (REDD+), assure the legality of forest products, certify responsible management, and devolve control over forests to empowered local communities.

Quantifying mammal biodiversity co-benefits in certified tropical forests

Article

Mar 2017

Aim Financial incentives to manage forests sustainably, such as certification or carbon storage payments, are assumed to have co‐benefits for biodiversity conservation. This claim remains little studied for rain forest mammals, which are particularly threatened, but challenging to survey. Location Sabah, Malaysia, Borneo. Methods We used photographic data from three commercial forest reserves to show how community occupancy modelling can be used to quantify mammalian diversity conservation co‐benefits of forest certification. These reserves had different management histories, and one was certified by the Forest Stewardship Council. Results Many threatened species occupied larger areas in the certified reserve. Species richness, estimated per 200 × 200‐m grid cell throughout all reserves, was higher in the certified site, particularly for threatened species. The certified reserve held the highest aboveground biomass. Within reserves, aboveground biomass was not strongly correlated with patterns of mammal richness (Spearman's rho from 0.03 to 0.32); discrepancies were strongest along reserve borders. Main conclusions Our approach provides a flexible and standardized tool to assess biodiversity and identify winners of sustainable forestry. Inferring patterns of species richness from camera‐trapping carries potential for the objective designation of high conservation value forest. Correlating species richness with aboveground biomass further allows evaluating the biodiversity co‐benefits of carbon protection. These advantages make the present approach an ideal tool to overcome the difficulties to rigorously quantify biodiversity co‐benefits of forest certification and carbon storage payments.

Using certified timber extraction to benefit jaguar and ecosystem conservation

Article

Dec 2016

The jaguar Panthera onca requires large areas of relatively intact habitats containing adequate amounts of prey to survive. Since a substantial portion of jaguar range occurs outside of strict protected areas, there is a need for economic incentives for habitat conservation, which carefully managed selective logging can provide. Forest Stewardship Council and Pan European Forest Council certifications intended to regulate wood extraction to maintain the ecological functions of forests require evidence of biodiversity and ecosystem conservation. We draw on twelve surveys across four countries and a range of biomes to present evidence that adequate logging management can maintain jaguar populations, but that they are at risk without efficient control of secondary impacts of access and hunting. Where resident, the presence of jaguars can serve as an indication that the ecological requirements of certified timber extraction are being met. We present a gradient of rigor for monitoring, recommending cost-effective options.

Spatial Capture-recapture: First Edition

Article

Sep 2013

Spatial Capture-Recapture provides a comprehensive how-to manual with detailed examples of spatial capture-recapture models based on current technology and knowledge. Spatial Capture-Recapture provides you with an extensive step-by-step analysis of many data sets using different software implementations. The authors approach is practical - it embraces Bayesian and classical inference strategies to give the reader different options to get the job done. In addition, Spatial Capture-Recapture provides data sets, sample code and computing scripts in an R package.

Secr–spatially explicit capture–recapture in R

Article

Jan 2011

Murray Efford

This document provides an overview of secr 2.3, an R package for spatially explicit capture–recapture analysis (SECR). It includes some background on SECR, an outline of the package, and a more detailed description of how models are implemented. See Appendix 1 for a glimpse of secr in action. For details of how to use secr see the help pages and vignettes.

Maintaining ecosystem function and services in logged tropical forests

Article

Jul 2014
TRENDS ECOL EVOL

Vast expanses of the world’s tropical forests have been or will be impacted by the cutting and harvest of trees for timber. We evaluate the environmental impacts of such ‘selective logging’ in natural forests and conclude that these logged forests typically retain most of their biodiversity and associated ecosystem functions, as well as their carbon, climatic and soil-hydrological services. Unfortunately, the values of logged forests are often overlooked in conservation plans and related research, leaving them vulnerable to further degradation, including post-logging clearing, fires and hunting. Because logged tropical forests are very extensive, functionally important, and provide core ecosystem services, efforts to expand their role in conservation strategies are urgently needed. Key priorities are improving harvest practices to reduce negative impacts on ecosystem functions and services, and preventing the rapid conversion and loss of logged forests.

Thresholds of Logging Intensity to Maintain Tropical Forest Biodiversity

Article

Aug 2014
CURR BIOL

Primary tropical forests are lost at an alarming rate, and much of the remaining forest is being degraded by selective logging. Yet, the impacts of logging on biodiversity remain poorly understood, in part due to the seemingly conflicting findings of case studies: about as many studies have reported increases in biodiversity after selective logging as have reported decreases. Consequently, meta-analytical studies that treat selective logging as a uniform land use tend to conclude that logging has negligible effects on biodiversity. However, selectively logged forests might not all be the same. Through a pantropical meta-analysis and using an information-theoretic approach, we compared and tested alternative hypotheses for key predictors of the richness of tropical forest fauna in logged forest. We found that the species richness of invertebrates, amphibians, and mammals decreases as logging intensity increases and that this effect varies with taxonomic group and continental location. In particular, mammals and amphibians would suffer a halving of species richness at logging intensities of 38 m(3) ha(-1) and 63 m(3) ha(-1), respectively. Birds exhibit an opposing trend as their total species richness increases with logging intensity. An analysis of forest bird species, however, suggests that this pattern is largely due to an influx of habitat generalists into heavily logged areas while forest specialist species decline. Our study provides a quantitative analysis of the nuanced responses of species along a gradient of logging intensity, which could help inform evidence-based sustainable logging practices from the perspective of biodiversity conservation.

High jaguar densities and large population sizes in the core habitat of the southwestern Amazon

Article

Mar 2013
BIOL CONSERV

Estimating jaguar densities with camera traps: Problems with current designs and recommendations for future studies

Article

Mar 2013
BIOL CONSERV

Using occupancy models to investigate space partitioning between two sympatric large predators, the jaguar and puma in central Brazil

Article

Jan 2012

Coexistence of sympatric species is mediated by resource partitioning. Pumas occur sympatrically with jaguars throughout most of the jaguar's range but few studies have investigated space partitioning between both species. Here, camera trapping and occupancy models accounting for imperfect detection were employed in a Bayesian framework to investigate space partitioning between the jaguar and puma in Emas National Park (ENP), central Brazil. Jaguars were estimated to occupy 54.1% and pumas 39.3% of the sample sites. Jaguar occupancy was negatively correlated with distance to water and positively correlated with the amount of dense habitat surrounding the camera trap. Puma occupancy only showed a weak negative correlation with distance to water and with jaguar presence. Both species were less often present at the same site than expected under independent distributions. Jaguars had a significantly higher detection probability at cameras on roads than at off-road locations. For pumas, detection was similar on and off-road. Results indicate that both differences in habitat use and active avoidance shape space partitioning between jaguars and pumas in ENP. Considering its size, the jaguar is likely the competitively dominant of the two species. Owing to its habitat preferences, suitable jaguar habitat outside the park is probably sparse. Consequently, the jaguar population is likely largely confined to the park, while the puma population is known to extend into ENP's surroundings.

Forest concessions in the Maya Biosphere Reserve, Guatemala: A decade later

Article

Nov 2011
Fuel Energ Abstr

In the Multiple-Use Zone of Guatemala’s Maya Biosphere Reserve, the usufruct rights to timber and non-timber forest resources were granted through concession agreements to 12 community organizations and two private timber companies in the late 1990s and early 2000s. After more than a decade, some concessions are successfully managing forests for multiple uses while others have had limited success or failed completely. This paper provides a management unit-based analysis and evaluation of the evolution of these forest concessions. First, we present a critical assessment of the current state of ecological integrity, socio-economic development, governance, and financing within each of the 14 forest concessions, using a series of quantitative and qualitative indicators. Next, we categorize the different trajectories that the concessions have experienced, and describe the key biophysical, socio-economic, and market events and drivers that may have influenced their outcomes. Lastly, we provide suggestions for the continued consolidation of multiple-use forest management practices in the Maya Biosphere Reserve, and draw out lessons for multiple-use forest management elsewhere in the tropics.

Comparison of diets of the acouchy, agouti and paca, the three largest terrestrial rodents of French Guianan forests

Article

Nov 2006
J TROP ECOL

Olivier Henry

The diets of the acouchy Myoprocta exilis, agouti Dasyprocta leporina and paca Agouti paca, the three largest terrestrial rodents of French Guiana forests, were investigated from stomachs collected over several years. These species are primarily frugivores. The percentage of fruit in their diet decreased, and seasonal variation increased from the smallest species, the acouchy, to the largest, the paca (contents in dry mass: respectively, 98.5% ± 0.6%, 87.4% ± 3.5%, and 83.9% ± 7.6%). They differed from each other in the proportions of pulp and secondary foods (leaves, fibre, insects) consumed annually as well as seasonally. Dietary diversity in the acouchy was half that of the two other species. The seasonal variation in consumption of different fruit parts and of secondary foods by these species corresponded well with the fruit production in the forest, and was linked to their reproductive events. Overall, the diets of these three large rodents appeared intermediate between the small rodent species and the artiodactyls (peccaries and brocket deer) inhabiting the same areas, which also concords with their body mass and their place within the guild of terrestrial mammals.

Modeling community dynamics based on species-level abundance models from detection/nondetection data

Article

Dec 2010
J APPL ECOL

1. In large-scale field surveys, a binary recording of each species’ detection or nondetection has been increasingly adopted for its simplicity and low cost. Because of the importance of abundance in many studies, it is desirable to obtain inferences about abundance at species-, functional group-, and community-levels from such binary data. 2. We developed a novel hierarchical multi-species abundance model based on species-level detection/nondetection data. The model accounts for the existence of undetected species, and variability in abundance and detectability among species. Species-level detection/nondetection is linked to species-level abundance via a detection model that accommodates the expectation that probability of detection (at least one individuals is detected) increases with local abundance of the species. We applied this model to a 9-year dataset composed of the detection/nondetection of forest birds, at a single post-fire site (from 7 to 15 years after fire) in a montane area of central Japan. The model allocated undetected species into one of the predefined functional groups by assuming a prior distribution on individual group membership. 3. The results suggest that 15–20 species were missed in each year, and that species richness of communities and functional groups did not change with post-fire forest succession. Overall abundance of birds and abundance of functional groups tended to increase over time, although only in the winter, while decreases in detectabilities were observed in several species. 4. Synthesis and applications. Understanding and prediction of large-scale biodiversity dynamics partly hinge on how we can use data effectively. Our hierarchical model for detection/nondetection data estimates abundance in space/time at species-, functional group-, and community-levels while accounting for undetected individuals and species. It also permits comparison of multiple communities by many types of abundance-based diversity and similarity measures under imperfect detection.

Impacts of forest fragmentation on species richness: A hierarchical approach to community modelling

Article

Jun 2009
J APPL ECOL

1. Species richness is often used as a tool for prioritizing conservation action. One method for predicting richness and other summaries of community structure is to develop species-specific models of occurrence probability based on habitat or landscape characteristics. However, this approach can be challenging for rare or elusive species for which survey data are often sparse. 2. Recent developments have allowed for improved inference about community structure based on species-specific models of occurrence probability, integrated within a hierarchical modelling framework. This framework offers advantages to inference about species richness over typical approaches by accounting for both species-level effects and the aggregated effects of landscape composition on a community as a whole, thus leading to increased precision in estimates of species richness by improving occupancy estimates for all species, including those that were observed infrequently. 3. We developed a hierarchical model to assess the community response of breeding birds in the Hudson River Valley, New York, to habitat fragmentation and analysed the model using a Bayesian approach. 4. The model was designed to estimate species-specific occurrence and the effects of fragment area and edge (as measured through the perimeter and the perimeter/area ratio, P/A), while accounting for imperfect detection of species. 5. We used the fitted model to make predictions of species richness within forest fragments of variable morphology. The model revealed that species richness of the observed bird community was maximized in small forest fragments with a high P/A. However, the number of forest interior species, a subset of the community with high conservation value, was maximized in large fragments with low P/A. 6. Synthesis and applications. Our results demonstrate the importance of understanding the responses of both individual, and groups of species, to environmental heterogeneity while illustrating the utility of hierarchical models for inference about species richness for conservation. This framework can be used to investigate the impacts of land-use change and fragmentation on species or assemblage richness, and to further understand trade-offs in species-specific occupancy probabilities associated with landscape variability.

Cockscomb Revisited: Jaguar Diet in the Cockscomb Basin Wildlife Sanctuary, Belize1

Article

Jun 2006
BIOTROPICA

The Cockscomb Basin Wildlife Sanctuary, Belize was established in 1986 following Rabinowitz and Nottingham's 1986 study on jaguar diet and distribution. In 2002, we reexamined jaguar diet following two decades of mitigated human hunting of jaguar prey. We observed high overlap between historical and current jaguar diet constructs. Nine-banded armadillo remained the most frequently consumed prey item. However, collared peccary consumption increased by nearly 20 percent while dietary breadth decreased by 60 percent presumably reflecting increased prey availability following reduced human hunting pressure.

Short-term effects of reduced-impact logging on eastern Amazon fauna

Article

Aug 2006
FOREST ECOL MANAG

In Amazonia, the effect of logging on fauna and the ability of reduced-impact logging (RIL) techniques to conserve the ecological integrity of forests is not well understood. In this study, we evaluated the short-term effect of RIL on species richness, abundance and composition of native Amazonian fauna (ants, arachnids, birds and mammals) 6 months after logging. We evaluated the response of fauna in pre- and post-logging treatments in 2–4 plots of 100 ha for each annual production area of three different sites in Para state, Brazil. Arthropods were sampled with pitfall traps in 2002, and diurnal birds and mammals were recorded using line transect methodology in 2002 and 2003. All groups were sampled between April and July, when there was no logging activity. We predicted that animal assemblages in RIL sites would be similar to the pre-logging sites as techniques were designed to minimize damages. In our study sites, logging intensity averaged 19 m3 ha−1. Overall, the effect of RIL on fauna was minor. The major changes were an increase in species richness of invertebrates and birds, confirming the expected pattern after recent disturbance. Mammals showed no changes in richness, abundance and composition. Arachnids were the only group showing responses in all three ecological variables. The low intensity of logging, and the connectivity with a matrix of logged and unlogged forests, may have promoted rapid recolonization at our study sites. The lower species loss in RIL forests compared to other types of land use in Amazonia highlights the value of this technique for conservation purposes among prominent economical activities.

Differential Use of Trails by Forest Mammals and the Implications for Camera‐Trap Studies: A Case Study from Belize

Article

Jan 2010
BIOTROPICA

Relative abundance indices are often used to compare species abundance between sites. The indices assume that species have similar detection probabilities, or that differences between detection probabilities are known and can be corrected for. Indices often consist of encounter frequencies of footprints, burrows, markings or photo captures along trails or transect lines, but the assumption of equal detection probabilities is rarely validated. This study analyzes detection probabilities of a range of Neotropical mammals on trails in dense secondary forests, using camera-trap and track data. Photo captures of the two large cats, jaguars (Panthera onca) and pumas (Puma concolor), were correlated solely with trail variables, while photo captures of their potential prey species had no correlation or negative correlation with trail variables. The Neotropical mammals varied greatly in their tendency to follow or cross trails based on footprints surveys. This indicates that camera locations on trails will have varying detection probability for these Neotropical mammals. Even the two similar-sized jaguars and pumas, occupying relatively similar niches, differed subtly in their use of trails. Pumas followed trails more completely while jaguars were more likely to deviate from trails. The ecological significance of these findings is that jaguars seem to be more willing to use the forest matrix away from trails than do pumas. We conclude that trail-based indices, such as photographic captures or tracks along trails, are not appropriate for comparison between Neotropical species, and not even between relatively similar species like jaguars and pumas.

Beyond Reserves: A Research Agenda for Conserving Biodiversity in Human‐modified Tropical Landscapes

Article

Mar 2009
BIOTROPICA

To truly understand the current status of tropical diversity and to forecast future trends, we need to increase emphasis on the study of biodiversity in rural landscapes that are actively managed or modified by people. We present an integrated landscape approach to promote research in human-modified landscapes that includes the effects of landscape structure and dynamics on conservation of biodiversity, provision of ecosystem services, and sustainability of rural livelihoods. We propose research priorities encompassing three major areas: biodiversity, human–environment interactions, and restoration ecology. We highlight key areas where we lack knowledge and where additional understanding is most urgent for promoting conservation and sustaining rural livelihoods. Finally, we recommend participatory and multidisciplinary approaches in research and management. Lasting conservation efforts demand new alliances among conservation biologists, agroecologists, agronomists, farmers, indigenous peoples, rural social movements, foresters, social scientists, and land managers to collaborate in research, co-design conservation programs and policies, and manage human-modified landscapes in ways that enhance biodiversity conservation and promote sustainable livelihoods.

Terrestrial wildlife response to logging and fire in a Bolivian tropical humid forest

Article

Jan 2002

Logging and wildfire are significant anthropogenic disturbance agents in tropical forests. We compared the abundance and species richness of selected terrestrial wildlife taxa including small mammals, amphibians, reptiles, and terrestrial invertebrates in areas burned by wildfire and then logged and in adjacent undisturbed areas of a tropical humid forest in Bolivia. Disturbed areas had 24% less canopy cover than undisturbed areas but had 2.6 times the cover of large woody debris. Understory cover did not differ between disturbed and undisturbed areas. Small mammal abundance and species richness in disturbed areas were 43 and 70% higher, respectively, than in adjacent undisturbed areas. Herpetofaunal abundance did not differ significantly among disturbed and undisturbed areas, but trends for higher abundance were observed for both reptiles and amphibians in disturbed areas. Herpetofaunal species richness was significantly higher in disturbed compared to undisturbed areas. Total terrestrial invertebrate abundance, as estimated by pitfall traps, was significantly higher in undisturbed compared to disturbed areas mostly due to higher abundances of Formicidae and Blattidae. However, two invertebrate groups, Orthoptera and Lepidoptera (larvae) were more abundant in disturbed areas. Wildlife conservation strategies for areas where logging or wildfire occur should take into account species- or guild-specific responses to these disturbance agents.

The future of tropical species in secondary forests: A quantitative review

Article

Dec 2009
BIOL CONSERV

Deforestation and degradation of tropical old-growth forests has the potential to cause catastrophic species extinctions. In this review, we assess whether regenerating secondary forests (SF) can support species typically found in old-growth forest (OG) and so prevent extinctions. We review 65 studies that compare faunal diversity in SF and corresponding OG, and compare the similarity of species composition both within and between these two forest types using the Sorensen, Morisita–Horn and Sorensen–Chao indices. Comparisons between traditional similarity indices and Sorensen–Chao, which minimizes sampling biases, indicated that limited sampling effort consistently reduced apparent similarity between SF and OG and that similarity between SF and OG is actually higher than previously appreciated. Similarity, which ranges from 0 to 1, varied from 0.49 to 0.92 between replicate OG sites and was correlated with similarity between SF and OG. This correlation might be an artefact of variation among studies in sampling effort, especially for vertebrates where small samples reduce apparent similarity across all comparisons, as well as a real effect of variation among studies in landscape heterogeneity and the presence of species with patchy distributions. Therefore, similarity between SF and OG cannot be interpreted without an understanding of background variation in OG. Similarity between different SF sites provided no evidence that disturbance specialists dominate SF. Similarity to OG increased rapidly with SF age; when SF was contiguous with OG; when SF was growing in small clearings; and after low intensity land uses including clearing only, shifting agriculture and tree plantations. This describes the most frequently observed tropical SF; isolated from roads and on hilly terrain unsuitable for mechanized agriculture. Thus, our analyses indicate that tropical SF can play an important role in biodiversity conservation particularly when OG forests are nearby. An important caveat remains, however. Abundance, geographic range and levels of habitat specialization are often related. Widespread, abundant, habitat generalists might dominate similarity analyses even when relatively rare OG specialists are present. Additional species-level analyses of habitat specialization will be needed before the conservation value of tropical SF is fully understood.

Estimating the density of a jaguar population in the Brazilian Pantanal using camera-traps and capture-recapture sampling in combination with GPS radio-telemetry

Article

May 2006
BIOL CONSERV

The jaguar (Panthera onca) is the largest feline in the Americas and third largest world-wide, smaller in size only to the tiger (P. tigris) and lion (P. leo). Yet, in comparison, relatively few studies on jaguar population densities have been conducted and baseline data for management purposes are needed. Camera trapping and capture–recapture sampling methods were used to estimate the size of a jaguar population in the Pantanal’s open wet grassland habitat, an important area for the long-term survival of the species. This study is the first jaguar population estimate conducted in co-operation with a GPS-telemetry study providing an important opportunity for comparing different methods of density estimation. An accessible area within a 460 km2 privately-owned ranch was sampled with equal effort during the dry seasons of 2003 and 2004. Thirty-one and twenty-five individual jaguars were identified in 2003 and 2004, respectively. Estimates of jaguar abundance were generated by program CAPTURE. Density estimates were produced according to different methods used to calculate the effectively sampled areas which ranged from 274 to 568 km2. For 2003, the currently-used mean maximum distance moved (MMDM) method produced a density of 10.3 jaguars/100 km2, while GPS-telemetry-based calculations produced a mean density of 6.6 jaguars/100 km2. For 2004, the MMDM method produced an estimate of 11.7 jaguars/100 km2 while GPS-telemetry calculations produced a density of 6.7 jaguars/100 km2. Our results suggest that the widely-used MMDM method used to calculate effectively sampled areas is significantly under-reflecting maximum distances moved by jaguars and their range-use and, thereby, considerably inflating cat density estimates. This overestimation could place a population in a difficult situation by lengthening the time taken to initiate protection measures because of underestimating the risk to that population.

Do responsibly managed logging concessions adequately protect jaguars and other large and medium-sized mammals? Two case studies from Guatemala and Peru

Abstract

No full-text available

Recommended publications

Request for Tenders for Project: Applying Behavioral Techniques Reducing Purchases of Wildlife Produ...

When roads appear jaguars decline: Increased access to an Amazonian wilderness area reduces potentia...