Jorge A. Ahumada

Jorge A. Ahumada
Conservation International

Doctor of Philosophy

About

111
Publications
48,100
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4,003
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Publications

Publications (111)
Article
Full-text available
The spatial aggregation of species pairs often increases with the ecological similarity of the species involved. However, the way in which environmental conditions and anthropogenic activity affect the relationship between spatial aggregation and ecological similarity remains unknown despite the potential for spatial associations to affect species...
Article
Full-text available
The Amazon forest has the highest biodiversity on Earth. However, information on Amazonian vertebrate diversity is still deficient and scattered across the published, peer-reviewed, and gray literature and in unpublished raw data. Camera traps are an effective non-invasive method of surveying vertebrates, applicable to different scales of time and...
Article
Full-text available
The structure of forest mammal communities appears surprisingly consistent across the continental tropics, presumably due to convergent evolution in similar environments. Whether such consistency extends to mammal occupancy, despite variation in species characteristics and context, remains unclear. Here we ask whether we can predict occupancy patte...
Article
Full-text available
Averting human‐induced extinctions will require strong policy commitments that comprehensively address threats to species. A new Global Biodiversity Framework is currently being negotiated by the world’s governments through the Convention on Biological Diversity. Here we explored how the suggested targets in this framework could contribute to reduc...
Article
Full-text available
The Amazon forest has the highest biodiversity on earth. However, information on Amazonian vertebrate diversity is still deficient and scattered across the published, peer‐reviewed and grey literature and in unpublished raw data. Camera traps are an effective non‐invasive method of surveying vertebrates, applicable to different scales of time and s...
Preprint
Full-text available
Most animals follow distinct daily activity patterns reflecting their adaptations1, requirements, and interactions2-4. Specific communities provide specific opportunities and constraints to their members that further shape these patterns3,4. Here, we ask whether community-level diel activity patterns among long-separated biogeographic regions diffe...
Article
Full-text available
The lives lost and economic costs of viral zoonotic pandemics have steadily increased over the past century. Prominent policymakers have promoted plans that argue the best ways to address future pandemic catastrophes should entail, “detecting and containing emerging zoonotic threats.” In other words, we should take actions only after humans get sic...
Article
Full-text available
The establishment of protected areas (PAs) is a central strategy for global biodi- versity conservation. While the role of PAs in protecting habitat has been high- lighted, their effectiveness at protecting mammal communities remains unclear. We analyzed a global dataset from over 8671 camera traps in 23 countries on four continents that detected 3...
Article
Tropical forests are the most diverse and productive ecosystems on Earth. While better understanding of these forests is critical for our collective future, until quite recently efforts to measure and monitor them have been largely disconnected. Networking is essential to discover the answers to questions that transcend borders and the horizons of...
Article
Full-text available
O objetivo foi abordar um mosaico de vegetação de savana (áreas marginais-MS e disjuntas-DS) no Cerrado Setentrional Brasileiro para investigar o papel desempenhado por fatores ambientais como determinantes da organização comunitária em escala espacial, a fim de compreender os padrões divergentes ao longo de uma gradiente ambiental. Analisamos pred...
Article
Tropical forests are the most diverse and productive ecosystems on Earth. While better understanding of these forests is critical for our collective future, until quite recently efforts to measure and monitor them have been largely disconnected. Networking is essential to discover the answers to questions that transcend borders and the horizons of...
Article
In a scenario where escalating human activities lead to several environmental changes and, consequently, affect mammal abundance and distribution, β-diversity may increase due to differences among sites. Using the ecological uniqueness approach, we analyzed β-diversity patterns of ground-dwelling mammal communities recorded through comprehensive ca...
Article
Tropical forests are the most diverse and productive ecosystems on Earth. While better understanding of these forests is critical for our collective future, until quite recently efforts to measure and monitor them have been largely disconnected. Networking is essential to discover the answers to questions that transcend borders and the horizons of...
Article
Full-text available
A variety of factors can affect the biodiversity of tropical mammal communities, but their relative importance and directionality remain uncertain. Previous global investigations of mammal functional diversity have relied on range maps instead of observational data to determine community composition. We test the effects of species pools, habitat he...
Preprint
Full-text available
Stopping human-induced extinctions will require strong policy commitments that comprehensively address threats to species. In 2021, a new Global Biodiversity Framework will be agreed by the Convention on Biological Diversity. Here we investigate how the suggested targets could contribute to reducing threats to threatened vertebrates, invertebrates,...
Article
Full-text available
The understanding of global diversity patterns has benefitted from a focus on functional traits and how they relate to variation in environmental conditions among assemblages. Distant communities in similar environments often share characteristics, and for tropical forest mammals, this functional trait convergence has been demonstrated at coarse sc...
Article
Full-text available
Bushmeat hunting is widely cited as cause for declines of wildlife populations throughout Africa. Forest duikers (Bovidae, Cephalophinae) are among the most exploited species. Whether current harvest rates imperil duikers is debated because of the difficulty of accurately assessing population trends. To assess population trends, we first reviewed l...
Article
Full-text available
Wildlife is an essential component of all ecosystems. Most places in the globe do not have local, timely information on which species are present or how their populations are changing. With the arrival of new technologies, camera traps have become a popular way to collect wildlife data. However, data collection has increased at a much faster rate t...
Article
Full-text available
Camera traps have existed since the 1890s (Kucera and Barrett 2011), but they weren’t widely used until the introduction of commercial infrared-triggered cameras in the early 1990s (Meek et al. 2014). Since then, millions, perhaps billions of camera trap images have been collected for many reasons, biodiversity monitoring being one of the key appli...
Article
Identifying the underlying drivers of species’ distributional dynamics is critical for predicting change and managing biological diversity. While anthropogenic factors such as climate change can affect species distributions through time, other naturally occurring ecological processes can also have an influence. Theory predicts that interactions bet...
Article
Full-text available
Carnivores have long been used as model organisms to examine mechanisms that allow coexistence among ecologically similar species. Interactions between carnivores, including competition and predation, comprise important processes regulating local community structure and diversity. We use data from an intensive camera-trapping monitoring program acr...
Data
Model selection analysis for occupancy (Ψ) and detection probability (p) used to evaluate the effect of time (sampling period) and study site on the habitat use of three sympatric felids, the jaguar (Panthera onca), puma (Puma concolor) and ocelot (Leopardus pardalis) in Neotropical forests. (DOCX)
Data
Prey species list and relative abundance index (images/100 ctdays) of small (< 15 Kg) and large prey (> 15Kg) of carnivores in our eight Neotropical study sites. (DOCX)
Data
Spearman’s rank correlation to test for collinearity among continuous covariates (ρ> 0.70). (DOCX)
Data
Coefficient of overlap (Δ1) with confidence intervals (CI lower/CI upper) and Watson’s two-sample test (two-sample U2) performed on pairwise comparisons between study sites. (DOCX)
Data
Single-species detection models used to evaluate the effects of covariates on the detection probability (p) of three sympatric felids, the jaguar (Panthera onca), puma (Puma concolor) and ocelot (Leopardus pardalis) in Neotropical forests. Detection probability was modelled as a function of elevation, NDVI, study site (site), large prey availabilit...
Data
Single-species occupancy models used to evaluate the effects of elevation (Elev.), distance to nearest water source (water), NDVI (ndvi), small prey’s availability (small) and large prey’s availability (large) on the habitat use of jaguar (Panthera onca), puma (Puma concolor) and ocelot (Leopardus pardalis) in Neotropical forests. (DOCX)
Data
Coefficient of overlap (Δ) with confidence intervals (CI lower/CI upper) and Watson’s two-sample test (two-sample U2) performed on pairwise comparisons between cat species per site. (DOCX)
Data
Single-species occupancy models used to evaluate best habitat factors and species interactions. Occupancy probability was modelled as a function of elevation (Elev.), distance to water (water), NDVI (ndvi), small prey’s availability (small), large prey’s availability (large) and occupancy estimates of each cat species (jaguar, puma and ocelot). (DO...
Data
Differences in the daily activity level (i. e., proportion of hours per day that an animal is active), standard errors (SE), Wald test (W) of Neotropical cats across the eight study sites (*Significant difference <0.05). (DOCX)
Article
Identifying ongoing changes in the distributions of species is critical for understanding and conserving biological diversity. Distributional shifts have been demonstrated in many ecosystems and taxa, yet the extent and nature of these changes remain largely undocumented for tropical forest mammals. Shifts over short time periods can be particularl...
Article
Identifying optimal sampling designs for detecting population-level declines is critical for optimizing expenditures by research and monitoring programmes. The Tropical Ecology Assessment and Monitoring (TEAM) network is the most extensive tropical camera-trap monitoring programme, but the effectiveness of its sampling protocol has not been rigorou...
Article
Full-text available
Much biodiversity data is collected worldwide, but it remains challenging to assemble the scattered knowledge for assessing biodiversity status and trends. The concept of Essential Biodiversity Variables (EBVs) was introduced to structure biodiversity monitoring globally, and to harmonize and standardize biodiversity data from disparate sources to...
Article
Full-text available
Debate about the conservation value of secondary habitats has tended to focus on tropical forests, increasingly recognizing the role of secondary forests for biodiversity conservation. However, there remains a lack of information about the conservation value of secondary savannas. Here, we conducted a camera trap survey to assess the effect of seco...
Article
Full-text available
Countries committed to implementing the Convention on Biological Diversity's 2011–2020 strategic plan need effective tools to monitor global trends in biodiversity. Remote cameras are a rapidly growing technology that has great potential to transform global monitoring for terrestrial biodiversity and can be an important contributor to the call for...
Article
Full-text available
Camera traps that capture photos of animals are a valuable tool for monitoring biodiversity. The use of camera traps is rapidly increasing and there is an urgent need for standardization to facilitate data management, reporting and data sharing. Here we offer the Camera Trap Metadata Standard as an open data standard for storing and sharing camera t...
Article
While there are well established early warning systems for a number of natural phenomena (e.g. earthquakes, catastrophic fires, tsunamis), we do not have an early warning system for biodiversity. Yet, we are losing species at an unprecedented rate, and this especially occurs in tropical rainforests, the biologically richest but most eroded biome on...
Conference Paper
Several recent developments within the regulatory and project finance realms have converged to create strong drivers for improving project biodiversity baseline assessment and monitoring in the oil and gas industry. Along with these drivers, enhanced guidance and approaches have emerged which support more robust and replicable biodiversity baseline...
Article
Full-text available
The conservation of tropical forest carbon stocks offers the opportunity to curb climate 43 change by reducing greenhouse gas emissions from deforestation and simultaneously conserve 44 biodiversity. However, there has been considerable debate about the extent to which carbon 45 storage will provide benefits to biodiversity in part because whether...
Article
Full-text available
Extinction rates in the Anthropocene are three orders of magnitude higher than background and disproportionately occur in the tropics, home of half the world’s species. Despite global efforts to combat tropical species extinctions, lack of high-quality, objective information on mammals and birds, representing 244 species from 15 tropical forest pro...
Data
Population occupancy status. By class (a), IUCN category (b), body mass (c), guild (d), landscape type (e), and hunting status (f). Bar height illustrates the relative frequencies of each occupancy status, and bar width illustrates the sample size. Asterisks indicate a significantly different occupancy status. See S2 Table for numerical data. (TIF)
Data
Occupancy status by TEAM site and guild. The proportion of populations with decreasing (orange), increasing (purple), unknown (gray), or stable (white) occupancy for each guild at each site; n = 511 populations. See S1 Table for site information corresponding to the three-letter site codes. Bar length illustrates the proportion of each occupancy st...
Data
Pairwise relationships between continuous site-level variables. Upper triangular portion of the matrix contains Pearson correlation coefficients, with the font size proportional to the correlation coefficient. Lower triangular portions of the matrix contain pairwise scatter plots to illustrate associations. “PAsize” is the log of the size of the pr...
Data
Summary information for TEAM sites. Including the full site name, site code, country, number of years of camera trap data, number of populations monitored by TEAM, percent of populations for each occupancy status, percent of monitored populations that were reported as hunted or not hunted, landscape connectivity, camera trap sampling area, protecte...
Data
Population occupancy status and monitoring duration. Frequency histogram of population trends based on the number of years of camera trap data (3–4 y [n = 8 sites, 270 populations], 5 y [n = 4 sites, 141 populations], or 6 y or more [n = 3 sites, 100 populations]). While the variance in occupancy trends decreased with additional years of data, the...
Data
Population occupancy over time. Each line depicts the trend of a particular species population monitored by TEAM. Color depicts significantly decreasing (orange), significantly increasing (purple), unknown (gray), or stable (black) occupancy trends. See S2 Table for numerical data. (TIF)
Data
Forest cover and landscape classification. (a) Green represents forest cover and brown represents non-forested cover for the ZOI of each protected area (Materials and Methods). Bold text is the code for each TEAM site. x- and y-axis labels are degrees latitude and longitude, respectively. (b) The UPGMA cluster analysis was based on two measures of...
Data
AIC comparison of univariate logistic regression models. For (a) the proportion of decreasing occupancy status populations per site and (b) the proportion of increasing occupancy status populations per site. For both decreasing and increasing occupancy status proportions, the null models with no covariates performed better (delta AIC > 2) than all...
Data
Monitored populations and associated attribute data. The following attributes are listed for each population: Class, Order, Family, Species, IUCN Red List Status (TH = Threatened, NT = Near Threatened, VU = Vulnerable, LC = Least Concern, DD = Data Deficient), Body Mass, Guild (Omnivore, Carnivore, Herbivore, Insectivore), Occupancy Coefficient Slo...
Article
Full-text available
Resumen Howler monkeys, genus Alouatta, are recognized as one of the most resistant primates to forest fragmentation. In this study a comparison of the home range, activity and diet of red howler monkeys (A. seniculus) was made between a continuous forest and a fragment in Meta, Colombia (Tinigua Park and Santa Rosa farm, respectively). Data was g...
Article
Full-text available
The conservation of tropical forest carbon stocks offers the opportunity to curb climate change by reducing greenhouse gas emissions from deforestation and simultaneously conserve biodiversity. However, there has been considerable debate about the extent to which carbon storage will provide benefits to biodiversity in part because whether forests t...
Conference Paper
Background/Question/Methods REDD+ advocates promote that maximizing conservation efforts for carbon storage in the form of above ground plant biomass will result in co-benefits for biodiversity conservation. While coarse-grained global analyses have supported the pattern that the greatest levels of terrestrial vertebrate biodiversity and carbon s...
Article
Full-text available
Medium-to-large mammals within tropical forests represent a rich and functionally diversified component of this biome; however, they continue to be threatened by hunting and habitat loss. Assessing these communities implies studying species' richness and composition, and determining a state variable of species abundance in order to infer changes in...