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Abstract

Large carnivore management is often contentious, particularly in jurisdictions where hunting and conservation efforts collide. Regulated hunting is a common management tool, yet relevant decisions are commonly taken in the absence of reliable population data and are driven by factors other than biological considerations. We used European large carnivore (brown bear Ursus arctos, wolf Canis lupus and Eurasian lynx Lynx lynx) management to evaluate the biological plausibility of reported population estimates used in hunting decisions. We used Romania as a test case as this region is not only data-poor, but the public and private game managers are beneficiaries of revenue from hunting activities. We assessed the following: (i) how population growth rates calculated from reported abundances between 2005 and 2012 compared to published growth rates empirically derived from European and North American populations; (ii) whether biological unrealism compounded through time by testing whether reported estimates fell within the bounds of biologically plausible trajectories; and (iii) the relationship between the occurrence of biologically unrealistic estimates and financial incentives (amount of hunting). For U. arctos, which generates high revenue, estimated annual population growth rates were frequently greater than maximum published growth rates (up to 1·5 for reported versus 1·136 in the literature). Reported estimates were greater than maximum simulated populations in 32% of cases, and the difference was positively correlated with hunting (rs = 0·576). Population growth rates for C. lupus overshot the maximum published growth rate (1·35) less frequently, reported estimates were within the bounds of biologically plausible estimates (91% of cases), and there was a weak correlation between hunting and biologically unrealistic estimates (rs = 0·182). L. lynx population growth rates derived from reported estimates were lower than minimum simulated populations (60% of cases), and there was a weak correlation between hunting and biologically unrealistic estimates (rs = 0·164). Synthesis and applications. Our study suggests that comparing population estimates used by management agencies to demographic data obtained through rigorous peer-reviewed studies is a useful approach for evaluating the biological plausibility of wildlife data in data-poor systems, especially when management decisions might be influenced by non-scientific incentives.

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... Metoda actuală de estimare și caracterizare a populației de lup, la nivel de fond cinegetic, este una "clasică", cu o istorie lungă în România, însă nu are mecanisme clare de control a calității informațiilor colectate sau a rezultatelor. În consecință, uneori (sub 5% din cazuri) estimările realizate nu par a fi întotdeauna corelate cu biologia speciei (Popescu et al., 2016), existând abateri constante atât în sensul sub estimării cât și al supra estimării mărimii populației (Fig. 77). Corectitudinea informațiilor ca amenințare/presiune face referire la modul în care datele sunt raportate și interpretate fără a putea prezenta nivelul de precizie al rezultatelor, respectiv prin prisma utilizării doar a unui singur indicator, respectiv numărul de indivizi. ...
... Colectarea de informații corecte prin metode fundamentate științific și testate în condițiile geomorfologice și de habitat din România devine acțiune cheie în planificarea managementului, fiind agreat interdisciplinar că este nevoie de o mai bună abordare a monitorizării populației (Kaczensky et al. 2012, Cazacu et al.,2014, Popescu et al., 2016. De asemenea, managementul speciei în ariile naturale protejate se fundamentează pe informații privind mărimea și dinamica populației de lup, uneori informațiile gestionate, intrând in contradicție cu cele ale gestionarilor de fonduri cinegetice. ...
... De asemenea, managementul speciei în ariile naturale protejate se fundamentează pe informații privind mărimea și dinamica populației de lup, uneori informațiile gestionate, intrând in contradicție cu cele ale gestionarilor de fonduri cinegetice. (Popescu et al.,2016) Principala cauză a lipsei de informații corecte privind specia este lipsa resurselor alocate acțiunilor de cercetare și monitorizare a speciei. În prezent singurele resurse disponibile sunt cele justificate de managementul rețelei Natura 2000, resurse ce sunt alocate pe bază de concurs de proiecte. ...
... Lack of accurate estimates of population parameters such as abundance, or worse, use of biased information in decision-making may mislead the prioritization of conservation and management actions (Katzner et al., 2011;Gopalaswamy et al., 2015;Bischof et al., 2016). Understanding confounding factors influencing conservation practitioners and wildlife managers' judgments about imperiled species, such as those related with the status of populations or the expected impact of interventions, is required to improve current management and conservation practices (Popescu et al., 2016;Heeren et al., 2017). ...
... Contentious debates about the population estimates of the brown bear (Ursus arctos) is such an example. Although effective conservation and management planning for bear populations require robust estimates of population parameters (Bischof et al., 2016;Morehouse and Boyce, 2016), failure to collect reliable data and use of biased approaches dictated by non-scientific incentives (e.g., public interest or trophy hunting) pose a central problem in supporting ecologically-meaningful actions (Kendall et al., 2009;Artelle et al., 2013;Popescu et al., 2016). Further, the conservation status and allocation of monitoring efforts for bear populations are contrasting across the species' global range (McLellan et al., 2017). ...
... Based on this study, we recommend wildlife managers in Iran and elsewhere to take into account reliable estimates of bear abundance, instead of the conventional count-based methods, experiential knowledge or perceptions that are prone to give a biased portrait of bear populations (Russell et al., 2012;Bischof et al., 2016;Popescu et al., 2016;Royle et al., 2017). As the majority of threatened terrestrial megafauna persists in developing countries (Ripple et al., 2016) with limited capacity of obtaining reliable monitoring data, it is important that the focus of research would be allocated on supporting evidencebased conservation actions, and test the reliability of current sources of information for the monitoring of populations. ...
Article
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Lack of reliable information on the status of species often leads managers to exclusively rely on experiential knowledge, opinions or perceptions, usually derived from personnel associated with natural resource management agencies. Yet, the accuracy of these sources of information remains largely untested. We approached this challenge, which is particularly common for wildlife monitoring programs in developing countries, using a population of Asian brown bears (Ursus arctos) in the Iranian Caucasus as case study. We conducted a noninvasive, genetic, spatial capture-recapture (SCR) study to estimate bear density across a core protected area, Arasbaran Biosphere Reserve, and compared our estimate of bear abundance with rangers’ perceptions as collated through interviews. The perceived abundance of bears by local rangers was between 3 and 5 times higher than our SCR estimate of 40 bears (2.5–97.5% Bayesian Credible Intervals = 27–70; density: 4.88 bears/100 km2). Our results suggest that basing management of the local bear population on perceptions of population status may result in overestimating the likelihood of population persistence. Our findings offer a scientific baseline for an evidence-based conservation policy for brown bears in Iran, and the broader Caucasus Ecoregion. The majority of threatened terrestrial megafauna occur in developing countries, where collecting and analyzing demographic data remain challenging. Delayed conservation responses due to the lack of, or erroneous knowledge of population status of such imperiled species may have serious consequences.
... The highest brown bear densities, of up to 11 individuals/100 km 2 occur in Eastern Carpathians ( Cazacu et al. 2014, Popescu et al. 2017. However, no studies to date have documented the movement ecology of Romanian brown bears at individual and population levels, leading to suboptimal management strategies ( Popescu et al. 2016). ...
... km 2 ) might not be suitable for planning bear management and especially as a population census base unit, as done presently. Thus, GMUs as sampling units might be a biased approach that can lead to poor management decisions at the population level, such as overharvesting ( Popescu et al. 2016) or unnecessary supplementary feed- ing ( Selva et al. 2017). Planning further census techniques should consider that male home ranges overlap more GMUs than those of the females (see Figures 4 and 5), mostly as a result of the brown bear mating system (Dahle and Swenson 2003). ...
... Human disturbance caused by traditional activities such as logging, hunting, agriculture, could not be considered when describ- ing the movements, but it represents a key factor influencing brown bear movement and habitat selection (Martin et al. 2010), and should be considered in further stud- ies. Notably, our study supports the implementation of brown bear monitoring at a regional scale, rather than focusing on GMUs as the monitoring unit ( Popescu et al. 2016). As brown bears may use multiple GMUs annually or during a single season, a regional approach to monitoring based on remote cameras and track counts ( Popescu et al. 2017) or non-invasive DNA techniques ( Proctor et al. 2010) is likely to yield better results and will require coordination between multiple adjacent GMUs. ...
Article
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Brown bear movement patterns are driven by their opportunistic feeding behaviour, with their complex life history and seasonality playing an important role in habitat selection. Within a large unfragmented forest habitats persisting over decades in the Romanian Carpathians and a prohibitive hunting management during 40 years of communist centralised game management, information about brown bear movements and spatial ecology is lacking. Using data obtained from 13 brown bears fitted with GPS telemetry collars, we estimated home ranges and core activity areas and we investigated the daily, seasonal and altitudinal movements of brown bears in the Eastern Romanian Carpathians and surrounding high hills. The median MCP95% home ranges of brown bears was 629.92 km 2 and the median size of core activity areas (estimated as 50% kernel density) was 36.37 km 2 , with no significant differences between males and females. The mean daily distance travelled, measured as daily displacement length, was 1818 m and an analysis of seasonal movements indicated significant differences between seasons (greatest movements during the Hyperphagia season). The GPS-collared brown bears travelled between a minimum altitude measured at ~234 m and a maximum at ~1634 m. Analysing the spatial overlap between the estimated home range and the game management units (GMU) limits, we obtained a median number of 8 GMUs overlapping totally or partially with estimated home range polygons. Our study, using GPS telemetry, highlights the complex spatial ecology of the brown bear in the Romanian Carpathians, with larger home range size than those estimated in other European brown bear populations and with daily movements that vary by season and within a large altitude range. Our study supports the implementation of brown bear monitoring at a regional scale, rather than focusing on county level GMUs as the monitoring unit.
... Arching through Eastern and Central Europe, the Carpathian Mountains are an essential biogeographical corridor for European wolves, with official EC reports suggesting Romania has the largest population on the continent, estimated at 2,300 to 2,700 individuals (Kaczensky, Chapron, von Arx, Huber, Andrén, & Linnell, 2012). However, within Romania itself, the methodologies informing this official representation are disputed (Popescu, Artelle, Pop, Manolache, & Rozylowicz, 2016), leading to pilot studies applying a range of techniques to make monitoring more accurate. It is one of these projects that this paper introduces ( Figure 1). ...
... The European Commission-endorsed wolf Action Plan aims to standardize surveying and monitoring techniques to improve understandings of meta-populations and ecologies, and to help human-wolf co-existence accordingly (Boitani et al., 2015). Currently in Romania, individual game management units survey wildlife populations at the end of spring (Kaczsensky et al., 2012;Popescu et al., 2016). However, this strategy is potentially compromised by both negative, long-standing hunter perceptions of wolves (Popescu et al., 2016), as well as inappropriate spatial and temporal scales for monitoring. ...
... Currently in Romania, individual game management units survey wildlife populations at the end of spring (Kaczsensky et al., 2012;Popescu et al., 2016). However, this strategy is potentially compromised by both negative, long-standing hunter perceptions of wolves (Popescu et al., 2016), as well as inappropriate spatial and temporal scales for monitoring. Therefore, conservationists in both Romania and Europe are seeking more rigorous, scientific monitoring methodologies. ...
... Thus, identifying methods than be applied across large spatial and temporal scales is key to future sustainable management. Often monitoring programs in these cases are based on indices or "minimum counts" with no possibility to assess accuracy and potential biases inherent in the programs [46]. For instance, in the study by Popescu et al. [46], growth rates based on replicated population counts were compared with biological plausible growth rates based on reported demographic rates for brown bear, wolf (Canis lupus) and Eurasian lynx (Lynx lynx). ...
... Often monitoring programs in these cases are based on indices or "minimum counts" with no possibility to assess accuracy and potential biases inherent in the programs [46]. For instance, in the study by Popescu et al. [46], growth rates based on replicated population counts were compared with biological plausible growth rates based on reported demographic rates for brown bear, wolf (Canis lupus) and Eurasian lynx (Lynx lynx). While such comparison of monitoring data from data-poor systems with more robust demographic data to assess the biological plausibility of the observed data provides information about potential pitfalls related to relying solely on such data, the approach taken in our study suggest that in many cases combining the data sets afford greater opportunity to maximize inference from a variety of sources. ...
Article
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We developed a model for estimating demographic rates and population abundance based on multiple data sets revealing information about population age- and sex structure. Such models have previously been described in the literature as change-in-ratio models, but we extend the applicability of the models by i) using time series data allowing the full temporal dynamics to be modelled, by ii) casting the model in an explicit hierarchical modelling framework, and by iii) estimating parameters based on Bayesian inference. Based on sensitivity analyses we conclude that the approach developed here is able to obtain estimates of demographic rate with high precision whenever unbiased data of population structure are available. Our simulations revealed that this was true also when data on population abundance are not available or not included in the modelling framework. Nevertheless, when data on population structure are biased due to different observability of different age- and sex categories this will affect estimates of all demographic rates. Estimates of population size is particularly sensitive to such biases, whereas demographic rates can be relatively precisely estimated even with biased observation data as long as the bias is not severe. We then use the models to estimate demographic rates and population abundance for two Norwegian reindeer (Rangifer tarandus) populations where age-sex data were available for all harvested animals, and where population structure surveys were carried out in early summer (after calving) and late fall (after hunting season), and population size is counted in winter. We found that demographic rates were similar regardless whether we include population count data in the modelling, but that the estimated population size is affected by this decision. This suggest that monitoring programs that focus on population age- and sex structure will benefit from collecting additional data that allow estimation of observability for different age- and sex classes. In addition, our sensitivity analysis suggests that focusing monitoring towards changes in demographic rates might be more feasible than monitoring abundance in many situations where data on population age- and sex structure can be collected.
... The methods developed here can assist wildlife managers to develop targeted conservation actions to promote a 'Favourable Conservation Status' at European level (Trouwborst, Boitani & Linnell, 2016). For Romania, the lack of ecological data led in recent years to a suboptimal management of the brown bear population (Popescu et al., 2016), and our study directly addresses gaps in bear management and conservation. ...
... For example identifying regional and national-level habitat priorities is a critical step towards designing ecological networks targeted at maintaining a Favourable Conservation Status for brown bears in the European Union (Schmeller et al., 2008;Trouwborst et al., 2016). While many wildlife management systems may be characterized and limited by poor data on carnivore populations (Artelle et al., 2013;Popescu et al., 2016), our approach identifying high conservation value areas can be applied broadly in any management system including those characterized by low allocation of resources for wildlife research. By focusing on habitat conservation, a management system with limited biological data can advance the sustainable management and conservation of wildlife populations, until demographic and abundance data becomes available (Trisurat et al., 2010). ...
Conference Paper
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Recovery of large carnivores in the European human‐dominated landscapes has sparked a debate regarding the optimal landscape conditions in which carnivores can thrive and coexist with humans. Here, we use brown bears Ursus arctos in the Romanian Carpathians to test and develop a framework for identifying habitat conservation priorities based on a novel integration of resource selection functions, home‐range data and systematic conservation planning. We used a comprehensive GPS telemetry dataset from 18 individuals to (1) calculate sex‐specific seasonal home ranges and (2) characterize population‐level habitat selection. We then used systematic conservation planning software Zonation to identify contiguous areas of high conservation value for males and females using Manly's habitat selection ratios as weights for habitat layers, and home‐range information as a smoothing parameter for habitat connectivity. Home ranges were smallest during winter (median [IQR] for November–February: 28.2 km2 [9.8–42.4]), and largest during the intense‐feeding season (September–November: 127.3 km2 [62.2–288.5]), with males having larger home ranges across all seasons. Females consistently selected for mixed forest habitat during all seasons. Males selected mixed forest during winter; then switched to a rather generalist approach, selecting regenerating forest and mixed and coniferous forests during low‐feeding/reproduction and wild berries seasons. We identified large tracts of forest habitat (~14% of the landscape) that was selected across all seasons as key habitats for brown bear conservation in the Romanian Carpathians. Spatially, high‐value winter habitat was the most dissimilar for both males and females, suggesting that conservation actions should focus on protecting contiguous denning habitat. These key findings can inform the management and conservation of the brown bear population in the Romanian Carpathians by identifying critical intervention areas for maintaining landscape connectivity, enable transboundary management and contribute to maintaining Favourable Conservation Status, an important target of European Union Strategy for Biodiversity.
... However, without statistical oversight, such methods may fail to detect population changes or may provide misleading estimates, thus hindering effective conservation and management of large carnivore populations (Popescu, Artelle, Pop, Manolache, & Rozylowicz, 2016). ...
... Brown bear population monitoring in Romania relies on a mixture of track surveys and sightings at feeding stations by local wildlife managers; these data are pooled together by the national wildlife authorities yearly to estimate the total number of brown bears at county level (Cazacu et al., 2014). However, these monitoring methods ignore uncertainty, which compounded with the lack of statistical oversight, may yield unrealistically high population estimates (Popescu et al., 2016). Moreover, unsustainable quotas can trigger local declines of populations if they are implemented for long periods of time (Artelle et al., 2013;Packer et al., 2011). ...
Article
Full-text available
Accurate population size estimates are important information for sustainable wildlife management. The Romanian Carpathians harbor the largest brown bear (Ursus arctos) population in Europe, yet current management relies on estimates of density that lack statistical oversight and ignore uncertainty deriving from track surveys. In this study, we investigate an alternative approach to estimate brown bear density using sign surveys along transects within a novel integration of occupancy models and home range methods. We performed repeated surveys along 2-km segments of forest roads during three distinct seasons: spring 2011, fall-winter 2011, and spring 2012, within three game management units and a Natura 2000 site. We estimated bears abundances along transects using the number of unique tracks observed per survey occasion via N-mixture hierarchical models, which account for imperfect detection. To obtain brown bear densities, we combined these abundances with the effective sampling area of the transects, that is, estimated as a function of the median (± bootstrapped SE) of the core home range (5.58 ± 1.08 km 2) based on telemetry data from 17 bears tracked for 1-month periods overlapping our surveys windows. Our analyses yielded average brown bear densities (and 95% confidence intervals) for the three seasons of: 11.5 (7.8–15.3), 11.3 (7.4–15.2), and 12.4 (8.6–16.3) individuals/100 km 2. Across game management units, mean densities ranged between 7.5 and 14.8 individu-als/100 km 2. Our method incorporates multiple sources of uncertainty (e.g., effective sampling area, imperfect detection) to estimate brown bear density, but the inference fundamentally relies on unmarked individuals only. While useful as a temporary approach to monitor brown bears, we urge implementing DNA capture–recapture methods regionally to inform brown bear management and recommend increasing resources for GPS collars to improve estimates of effective sampling area.
... The species was extirpated from the Alps, Jura, and Dinaric Mountains during the 20th century; managers started reintroduction programs using individuals from Central and Eastern European populations ), yet success has been limited (Vandel et al. 2006;Mueller et al. 2020). Concomitantly, donor populations in Eastern Europe are lacking reliable density and demographic data (Rozylowicz et al. 2011;Popescu et al. 2016), such that removal of individuals, unsustainable hunting quotas of the prey base, and rapid deforestation, all may compromise population viability. ...
... This mosaic provides habitat, food, and space requirements for a viable population of Eurasian lynx, as well as other large carnivores and their ungulate prey (Salvatori et al. 2002;Chapron et al. 2014). Despite their importance for carnivore conservation in Europe in general, the Romanian Carpathian populations are remarkably understudied (Promberger-Fürpass et al. 2002;Rozylowicz et al. 2010); there is no science-based monitoring at a scale relevant to carnivores' spatial ecology, and lynx have the least data available for informing conservation (Popescu et al. 2016). ...
Article
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The Eurasian lynx (Lynx lynx) faces population declines in the western part of its range, and its ecological requirements are poorly understood in the eastern part of its range. The Romanian Carpathians harbor an intact large carnivore community, in which lynx co-occur with bears (Ursus arctos), wolves (Canis lupus), and humans (Homo sapiens), with which they potentially compete for ungulate prey. We provide a science-based estimate of lynx density and habitat use, combining non-invasive monitoring techniques (camera trapping) with spatially explicit capture-recapture models (SECR) in the Southern Carpathians of Romania. We sampled 59 and 76 trap stations during two monitoring sessions (winter and autumn), identified at least 30 individuals, from which we reconstructed encounter histories for 23 individuals. SECR modeling resulted in similar density estimates between winter and autumn (1.6 ± 0.39 SE and 1.7 ± 0.38 SE lynx/100 km 2 , respectively), but the cumulative number of lynx detected reached the asymptote faster during autumn, suggesting that monitoring prior to the mating season is preferable. Density varied within and across sessions with topography (slope), percent forest cover, and landscape heterogeneity (i.e., agricultural mosaic). Density hotspots shifted between low-altitude agricultural mosaic during winter and more rugged, mid-altitude forest stands during autumn. Estimated densities of lynx in the Romanian Carpathians are higher than those reported in the Alps or Slovak Carpathians, highlighting the importance of this population as a source both for natural recolonization and recent reintroduction programs. When used in an SECR framework, camera trapping is an efficient method for assessing spatial and temporal variation in lynx population density in the remote Romanian Carpathians. We recommend this methodology for improving lynx population estimates and to monitor lynx population trends nationwide.
... The methods developed here can assist wildlife managers to develop targeted conservation actions to promote a 'Favourable Conservation Status' at European level (Trouwborst, Boitani & Linnell, 2016). For Romania, the lack of ecological data led in recent years to a suboptimal management of the brown bear population (Popescu et al., 2016), and our study directly addresses gaps in bear management and conservation. ...
... For example identifying regional and national-level habitat priorities is a critical step towards designing ecological networks targeted at maintaining a Favourable Conservation Status for brown bears in the European Union (Schmeller et al., 2008;Trouwborst et al., 2016). While many wildlife management systems may be characterized and limited by poor data on carnivore populations (Artelle et al., 2013;Popescu et al., 2016), our approach identifying high conservation value areas can be applied broadly in any management system including those characterized by low allocation of resources for wildlife research. By focusing on habitat conservation, a management system with limited biological data can advance the sustainable management and conservation of wildlife populations, until demographic and abundance data becomes available (Trisurat et al., 2010). ...
Article
Full-text available
Recovery of large carnivores in the European human-dominated landscapes has sparked a debate regarding the optimal landscape conditions in which carnivores can thrive and coexist with humans. Here, we use brown bears Ursus arctos in the Romanian Carpathians to test and develop a framework for identifying habitat conservation priorities based on a novel integration of resource selection functions, home-range data and systematic conservation planning. We used a comprehensive GPS telemetry dataset from 18 individuals to (1) calculate sex-specific seasonal home ranges and (2) characterize population-level habitat selection. We then used systematic conservation planning software Zonation to identify contiguous areas of high conservation value for males and females using Manly's habitat selection ratios as weights for habitat layers, and home-range information as a smoothing parameter for habitat connectivity. Home ranges were smallest during winter (median [IQR] for November–February: 28.2 km2 [9.8–42.4]), and largest during the intense-feeding season (September–November: 127.3 km2 [62.2–288.5]), with males having larger home ranges across all seasons. Females consistently selected for mixed forest habitat during all seasons. Males selected mixed forest during winter; then switched to a rather generalist approach, selecting regenerating forest and mixed and coniferous forests during low-feeding/reproduction and wild berries seasons. We identified large tracts of forest habitat (~14% of the landscape) that was selected across all seasons as key habitats for brown bear conservation in the Romanian Carpathians. Spatially, high-value winter habitat was the most dissimilar for both males and females, suggesting that conservation actions should focus on protecting contiguous denning habitat. These key findings can inform the management and conservation of the brown bear population in the Romanian Carpathians by identifying critical intervention areas for maintaining landscape connectivity, enable transboundary management and contribute to maintaining Favourable Conservation Status, an important target of European Union Strategy for Biodiversity.
... In Romania, failure to engage all stakeholders in large carnivore management and conservation in HDLs led to reactive policy decisions and fueled conflict. In 2016, hunting of brown bears (Ursus arctos) (Romania harbors the largest number of brown bears in the European Union; approximately 6000 individuals; Zedrosser et al. 2001) and other large carnivores (lynx [Lynx lynx], wolf [Ca- nis lupus]) was banned by the Ministry of Environment in part because of the weak scientific basis for setting bear hunting quotas ( Popescu et al. 2016), the perceived influence of certain economic interests in determining annual quotas (i.e., trophy hunting in the case of bears), and intense public campaigns seeking a ban on hunting of protected large carnivores (WWF 2017). Because this policy change was implemented without due consideration of other measures to prevent human-large carnivore conflict and efficient compensation, some stakeholders responded by successfully requesting that the government ...
... Disciplinary and interdisciplinary approaches can provide important knowledge for understanding several aspects and challenges of human-large carnivore coexistence (column 1 in Fig. 2), but they may have limited power to leverage the deeper system changes needed to mainstream coexistence (column 4 in Fig. 2 & Table 1). For example, the disciplines of ecology, geography, and statistical modeling can yield robust results on the population dynamics of large carnivores ( Popescu et al. 2016), but these results may be perceived with skepticism by other sectors (e.g., wildlife management, as happened in Romania; T.H. & L.R., personal observation). Furthermore, social sciences can improve understanding of the various types of stakeholders, their interests and values, and the relationships between them (e.g., Jacobsen & Linnell 2016; Brazilian case study). ...
Article
Full-text available
Achieving coexistence between large carnivores and humans in human‐dominated landscapes (HDLs) is a key challenge for societies globally. This challenge cannot be adequately met with the current sectoral approaches to HDL governance and an academic community largely dominated by disciplinary sectors. Academia (universities and other research institutions and organizations) should take a more active role in embracing societal challenges around conservation of large carnivores in HDLs by facilitating cross‐sectoral cooperation to mainstream coexistence of humans and large carnivores. Drawing on lessons from populated regions of Europe, Asia, and South America with substantial densities of large carnivores, we suggest academia should better embrace the principles and methods of sustainability sciences and create institutional spaces for the implementation of transdisciplinary curricula and projects; reflect on research approaches (i.e., disciplinary, interdisciplinary, or transdisciplinary) they apply and how their outcomes could aid leveraging institutional transformations for mainstreaming; and engage with various institutions and stakeholder groups to create novel institutional structures that can respond to multiple challenges of HDL management and human–large carnivore coexistence. Success in mainstreaming this coexistence in HDL will rest on the ability to think and act cooperatively. Such a conservation achievement, if realized, stands to have far‐reaching benefits for people and biodiversity.
... The mountain sector of the Prahova Valley, located between Sinaia and Predeal, is characterized by the presence of natural forests, with European beech (Fagus sylvatica), Norway spruce (Picea abies), Silver fir (Abies alba), Mountain pine (Pinus mugo) and European larch (Larix decidua) being the dominating tree species. These high naturalness hotspots are unique refuges of large carnivores, such as the brown bear (Ursus arctos), Eurasian wolf (Canis lupus lupus) and Carpathian lynx (Lynx carpathicus) (Popescu et al., 2016;Rozylowicz et al., 2011). ...
... Wildlife management instruments targeting stable populations should be evidence-based. Therefore, decisions on quota harvesting need more granular data on wildlife population and future trends, instead of population estimates (Popescu et al., 2016). ...
Article
Human-wildlife interactions (HWI) are present in areas where wild animals and humans compete for limited space, sometimes resulting in potentially harmful conflicts on both sides. The upper Prahova Valley within the central Carpathian range of Romania represents an area where interactions between humans and wildlife can still be found, but potentially conflicting due to the presence of both large intact natural habitats and increasing human pressure over the environment. In our study, we hypothesize that an adequate understanding of the HWI problem involves analyses on landscape pattern, natural or human induced triggering factors, and local stakeholders’ perception of the phenomenon including the measures they consider suitable for optimizing their interactions with wild animals. Therefore, the goal of our paper was to analyse the characteristics of the HWI phenomenon in the upper Prahova Valley, based on exploring the local stakeholders’ perspective. The study methodology consists of three steps: (i) applying 450 questionnaires to local stakeholders in order to extract HWI data; (ii) detecting the interconnection between various types of HWI and the perception of local people, using statistical and network approaches; and (iii) develop a set of recommendations which are applicable at both, local and regional decisional level in order to decrease the negative impact of HWI, enhance wildlife conservation strategies and promote a sustainable interactions with humans and mitigate potential conflicts that occur between humans and wildlife. The results indicate that the brown bear, wild boar and red fox were constantly increasing in HWI after 1990, while interactions with Eurasian wolf, stone marten, European polecat, roe deer and mountain viper were usually scarcer. The brown bear and wild boar were the prior species involved in conflict interactions with humans, such as the destruction of fences, orchards, or gardens. The bear was the only wildlife responsible for non-fatal human attacks. Locals consider the lack of wildlife food supply by the forest staff and the deficient forest management practices after 1990 to be the main triggering factors of these negative HWI. They perceive that the interactions with these animals pose a high risk to human security. Our results stand as a strong argument for a complex management system concerning the HWI phenomenon which adapts upper-level policies and governance decisions to both local stakeholder’s needs and wildlife management objectives to be achieved in order to attain a favorable conservation status.
... By contrast, the values underlying specific policies used in Western-based management systems are often neither recognized nor explicitly articulated. For example, some management decisions are assumed or claimed to be based purely on knowledge from natural sciences , despite sometimes contradicting evidence (e.g., Horwitz and Calver 1998, Popescu et al. 2016. However, although the natural sciences provide information on how the world works and may predict future outcomes (e.g., "will a particular action likely lead to population declines?"), ...
Article
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The prevalence of widespread, human-caused ecological degradation suggests that fundamental change is needed in how societies interact with the environment. In this paper we argue that durable models of environmental relationships already exist in approaches of place-based peoples, whose values connect people to their environments, provide guidance on appropriate behaviors, and structure sustained people-place relationships. To illustrate, we identify and discuss concordant values of indigenous peoples at opposite ends of the Pacific Ocean: the Māori of Aotearoa (New Zealand), and First Nations of the West Coast of Canada. We find that values of relatedness to, respect of, and reciprocity with other species and places correspond with sustained long-term relationships between people and places, and illustrate with examples from both regions. We propose that by integrating a values-led foundation into management broadly, values-led management could enable similar sustained relationships in places where they have been recently disrupted or where they are altogether lacking. We characterize values-led management as being founded on values that underpin stewardship-like relationships between people and place and that in turn guide related objectives, policies, and practices. We examine two contemporary values-led management plans that follow this structure, and provide additional examples of emergent values-led approaches elsewhere. From these we compile a set of questions that might guide the conception of place-based values-led management in decolonizing contexts, in contexts where people have a desire for place-based approaches but have not yet distilled foundational values for guidance, or in contexts where people have a united set of values but have not yet translated them into specific management approaches. We conclude by discussing both the challenges and learning opportunities that the resumption, or commencement, of values-led management might entail.
... The European wildcat (Felis silvestris) is a mesocarnivore that was once common in Europe and has also been extirpated and currently at the core of reintroduction programs in some European Union states. In this context, the Romanian Carpathians represent one of the few natural areas in Europe that still harbor intact viable populations of all three species and serve as a stronghold for carnivore populations in Europe, despite anthropogenic influences common (hunting, forestry, farming, and livestock production) (Popescu et al., 2016;Salvatori et al., 2002). ...
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The recovery of terrestrial carnivores in Europe is a conservation success story. Initiatives focused on restoring top predators require information on how resident species may interact with the re-introduced species as their interactions have the potential to alter food webs, yet such data are scarce for Europe.In this study, we assessed patterns of occupancy and interactions between three carnivore species in the Romanian Carpathians. Romania houses one of the few intact carnivore guilds in Europe, making it an ideal system to assess intraguild interactions and serve as a guide for reintroductions elsewhere.We used camera trap data from two seasons in Transylvanian forests to assess occupancy and co-occurrence of carnivores using multispecies occupancy models.Mean occupancy in the study area was highest for lynx (Ψwinter = 0.76 95% CI: 0.42-0.92; Ψautumn = 0.71 CI: 0.38-0.84) and wolf (Ψwinter = 0.60 CI: 0.34-0.78; Ψautumn = 0.81 CI: 0.25-0.95) and lowest for wildcat (Ψwinter = 0.40 CI: 0.19-0.63; Ψautumn = 0.52 CI: 0.17-0.78)We found that marginal occupancy predictors for carnivores varied between seasons. We also found differences in predictors of co-occurrence between seasons for both lynx-wolf and wildcat-wolf co-occurrence. For both seasons, we found that conditional occupancy probabilities of all three species were higher when another species was present.Our results indicate that while there are seasonal differences in predictors of occupancy and co-occurrence of the three species, co-occurrence in our study area is high.Terrestrial carnivore recovery efforts are ongoing worldwide. Insights into interspecific relations between carnivore species are critical when considering the depauperate communities they are introduced in. Our work showcases that apex carnivore coexistence is possible, but dependent on protection afforded to forest habitats and their prey base.
... Regulated harvesting (e.g., trapping, hunting) is a common, yet debated, wildlife management method. However, in many cases, harvesting may occur without a thorough understanding of the population size and demography, leading to detrimental effects on the long-term viability of the target species (e.g., Artelle et al., 2013Artelle et al., , 2018Popescu et al., 2016). The information in this study can serve as a source of information on the local carnivore populations, some of which appear to be vulnerable to additional sources of mortality (e.g., roadkill, disease). ...
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Carnivores act as top-down regulators in terrestrial ecosystems, and their occurrence and relative abundance is a result of complex interactions between food and habitat availability, human pressure (e.g., trapping, hunting, roadkill), and intraguild interactions (competition, predation). Eastern United States has a long history of human impact, which resulted in an altered carnivore community. Specifically, Ohio presents an interesting case for evaluating the relative roles of interspecific relations and habitat characteristics for shaping the carnivore community, as its carnivore community has a unique dynamics and composition: invasive coyote and red fox (Vulpes vulpes), and native bobcat (Lynx rufus), currently recovering and expanding its range, gray fox (Urocyon cinereoargenteus) declining at a fast pace, and the generalist raccoon (Procyon lotor) and Virginian opossum (Didelphis virginiana). We used 50 camera traps to collect presence/absence data in southeastern Ohio, USA. We hypothesized potential interactions between the six carnivores, and used land cover variables, as well as occupancy probabilities of interacting species, to parameterize to single-species occupancy models. We found that landscape composition at three different scales (500 and 1000 m buffer around camera locations, and 3 × 3 km grid cell) had little effect on species occurrence. We identified strong negative interspecific relations between carnivores, with bobcat occurrence being influenced by presence of coyotes, red fox occurrence by gray foxes, and raccoon occurrence by Virginia possums. While these findings cannot discriminate between habitat partitioning (spatial or temporal) and competition (direct or interference), they lend support to complex dynamics between invasive coyotes and red foxes and recovering (bobcat) and declining (gray fox) native carnivore species. In particular, the negative relation between the apex predator in our system, C. latrans, and L. rufus, raise further questions on whether direct competition from coyotes has the potential to slow bobcat population recovery. In the context of regulated trapping (ongoing for gray fox and potential season for bobcat), a better understanding of the carnivore intraguild relations can inform management and conservation actions targeted at minimizing the impact of competition on at-risk native species from non-native species.
... An advantage of modeling the reproductive rate using an exponential function is that X t ¼ log N t ð Þ follows a Gaussian autoregressive process which allows the use of standard tools, for example, the Kalman filter, for computing the likelihood. We choose instead to follow a Bayesian approach, fitting the models using Markov chain Monte Carlo (MCMC) methods implemented in JAGS (Plummer 2003) run through the package rjags (Plummer 2016) within the R computing environment (R Development Core Team 2016). The Bayesian approach has the advantage of, given a suitable choice of prior parameter distributions, providing a unified way of presenting probabilistic measures of uncertainty through posterior distributions. ...
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Time‐series models applied in the study of animal population dynamics commonly assume linearity on the log‐scale, leading to log‐normally distributed rates of increase. While this is often computationally convenient, in particular when performing statistical inference in the presence of observation error, it may lead to unrealistic predictions for animals with a limited reproduction. We introduce a model that includes an explicit bound on the reproductive rate of an individual, and apply this to a population time series of ungulates in Kruger National Park, South Africa. Due to observational error, the year‐to‐year increases in animal counts occasionally exceeded the maximal reproductive rate of the animals. In such cases, the traditional unbounded model showed a tendency of overfitting data, leading to unrealistic predictions of the underlying population increase. An observed increase above the maximal reproductive rate also provides empirical confirmation that observation error exists. The model with an explicit bound was able to utilize this in order to separate observational error from population process noise, which the traditional unbounded model was unable to do. We conclude that enforcing a strict upper bound on the reproductive rate of an animal population model may lead to more realistic statistical inference than commonly applied log‐linear models when an explicit bound on reproductive rate is known. We further conclude that introducing a bound on reproduction can greatly assist in separating observational error and population process noise for slow life histories, or more generally, when the rate of sampling is high compared to reproductive rates.
... Reliability is essential to build acceptance and support in management decisions and, ultimately, trust in managing authorities. Otherwise, speculation and distrust can emerge after decisions are made, and may undermine entire management or conservation strategies 1,3 . Incorrect population estimates may lead to misinterpretations of the status of populations, the impact of interventions (e.g., hunting quotas or culling programs), or the degree to which conservation goals have been achieved. ...
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Decision-makers in wildlife policy require reliable population size estimates to justify interventions, to build acceptance and support in their decisions and, ultimately, to build trust in managing authorities. Traditional capture-recapture approaches present two main shortcomings, namely, the uncertainty in defining the effective sampling area, and the spatially-induced heterogeneity in encounter probabilities. These limitations are overcome using spatially explicit capture-recapture approaches (SCR). Using wolves as case study, and non-invasive DNA monitoring (faeces), we implemented a SCR with a Poisson observation model in a single survey to estimate wolf density and population size, and identify the locations of individual activity centres, in NW Iberia over 4,378 km2. During the breeding period, posterior mean wolf density was 2.55 wolves/100 km2 (95%BCI = 1.87–3.51), and the posterior mean population size was 111.6 ± 18.8 wolves (95%BCI = 81.8–153.6). From simulation studies, addressing different scenarios of non-independence and spatial aggregation of individuals, we only found a slight underestimation in population size estimates, supporting the reliability of SCR for social species. The strategy used here (DNA monitoring combined with SCR) may be a cost-effective way to generate reliable population estimates for large carnivores at regional scales, especially for endangered species or populations under game management.
... Vrancea and Harghita), where the number of hunted bears is very high, the population increase (on paper) has been in some cases even 50%, i.e. four times higher than elsewhere in Europe or North America (CCMESI, 2017) . This data manipulation example might be explained by the promotion of a management aiming at authorizing the hunting campaigns, involving both Romanian and foreign citizens (Popescu et al., 2016). In Romania, the studies dealing with the distribution, ecology and ethology of Ursus arctos arctos are already notorious, as long as Romania comes first in Europe among the countries that shelter this species. ...
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The official assessments of the European Commission tell that Carpathian brown bear is a vulnerable species. The man-bear relationship must take into account three aspects of the bears' behavior: feeding, protection and aggressivity. The aim of the study is to analyze the typology of the relation between Ursus arctos arctos and Homo sapiens sapiens within the protected areas in the Harghita County (the Eastern Carpathians). The research methodology was the following: surveying the literature dealing with brown bear's ecology and ethology; undertaking field research; running questionnaires; monitoring the online environment. The results show that the shrinkage of the brown bear's habitat is directly proportional with forest shrinkage. The typology of the man-bear relationships includes commensalism, food competition and individual intolerance.
... Using culling as a management measure for the wolf has been shown to increase poaching as well [69,70]. In Romania, Popescu et al. [71] suggest that these factors may have a much higher impact on the wolf populations than they initially assumed in their study. It is therefore necessary to study the impact of wolves on prey to quantify how much wolf consumes. ...
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The Romanian wolf population, one of the largest in Europe, occupies a total home-range of 154500 km² and is spread across a variety of landscapes–from anthropized hills and plateaus to remote, densely forested mountains. However, this population is markedly understudied, and even basic knowledge of the species’ feeding habits is deficient. Wolf diet was assessed based on 236 scat samples collected between November 2013 and October 2014, by following pre-established transects (total length = 774 km). The study area (600 km²) is a multi-prey ecosystem in the southern sector of the Eastern Romanian Carpathians. Our results emphasize that more than 80% of the wolf diet is based on wild ungulates. The wild boar is clearly selected (D = 0.74) and is the most common species in the diet (Bio = 72%), while roe deer (Bio = 10%) and red deer (Bio = 5%) have a smaller contribution. Domestic species represented the second-largest prey category in both seasons. Among them, dog is a particularly important source of food (Bio 3.5–10.9%). Other domestic species (goat, sheep, horse) have marginal importance in the wolf diet and seasonal occurrence. Standardized niche breadths are low in both seasons (BAw = 0.07, BAs = 0.12), and a high degree of overlap in the resources used has been observed (Ôws = 0.99). Our study represents the first step towards understanding the wolf foraging behaviour in the Romanian Carpathians and is valuable to address the complex issues of wolf and wild ungulate population management and conservation.
... Choosing the best proxy data is crucial in the evaluation of the status of a species (Joseph et al. 2006), especially in poor data systems (Popescu et al. 2016). Data on the Italian populations of BG, PTA and PAR fit this definition, as already highlighted by the latest national reports on the application of the Birds Directive (Nardelli et al. 2015) and on conservation status of game species (Franzetti and Toso 2009). ...
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Information on the abundance of the Italian populations of black grouse (Lyrurus tetrix), Alpine rock ptarmigan (Lagopus muta helvetica) and Alpine rock partridge (Alectoris graeca saxatilis) rely only on extrapolations of local data to the national scale, since there is no national standardized survey. Consequently, their status is virtually unknown. We performed a first-ever assessment of a medium-term (1996–2014) population trend of these species using and comparing post-breeding count and bag data at hunting district scale. These data were collected from various authorities in charge of wildlife management and allowed us to test the influence of hunting policies on the estimated trends. Rock partridge showed a stable trend with numbers fluctuating between years, while there was evidence of a severe decline for rock ptarmigan. No general conclusion could be drawn for the black grouse, as we detected lack of consistency of count and bag data. Counts were greatly overdispersed as a result of an uneven count effort among hunting districts. Adding the game management authority as model covariate resulted in more robust trend estimations, suggesting a significant effect of different policies that emerged also as similar hunting pressure across species within authorities. Hunting effort variation over the time was instead negligible. Species-specific game management bias is discussed. Our results highlight the need for a survey scheme or guidelines to be applied uniformly at a national scale.
... However, they do not apply to large animals for various reasons. Populations of rare or elusive large mammals are difficult to control because they are usually secretive, lone, occur at low densities, and have large domestic ranges, which poses significant methodological problems for population estimation [64,65]. The elk population is rather small, so it is important to assess the effectiveness of monitoring in the field of hunting as an environmental protection measure for biological diversity support and endangered species preservation. ...
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Reliable information about wildlife is absolutely important for making informed management decisions. The issues with the effectiveness of the control and monitoring of both large and small wild animals are relevant to assess and protect the world’s biodiversity. Monitoring becomes part of the methods in wildlife ecology for observation, assessment, and forecasting of the human environment. World practice reveals the potential of the joint application of both proven traditional and modern technologies using specialized equipment to organize environmental control and management processes. Monitoring large terrestrial animals require an individual approach due to their low density and larger habitat. Elk/moose are such animals. This work aims to evaluate the methods for monitoring large wild animals, suitable for controlling the number of elk/moose in the framework of nature conservation activities. Using different models allows determining the population size without affecting the animals and without significant financial costs. Although, the accuracy of each model is determined by its postulates implementation and initial conditions that need statistical data. Depending on the geographical, climatic, and economic conditions in each territory, it is possible to use different tools and equipment (e.g., cameras, GPS sensors, and unmanned aerial vehicles), a flexible variation of which will allow reaching the golden mean between the desires and capabilities of researchers.
... The wildcat (Felis silvestris ) is a mesocarnivore that was once common in Europe, has also been extirpated, and currently at the core of reintroduction programs in some European Union states. In this context, the Romanian Carpathians represent one of the few natural areas in Europe that still harbor intact viable populations of all three species and serve as a stronghold for carnivore populations in Europe, despite anthropogenic influences common (hunting, forestry, farming, and livestock production) (Popescu et al., 2016;Salvatori et al., 2002). ...
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1. The recovery of terrestrial carnivores in Europe is a conservation success story. Initiatives focused on restoring top predators, require information on how resident species may interact with the re-introduced species as their interactions have the potential to alter food webs, yet such data are scarce for Europe. 2. In this study, we assessed patterns of occupancy and interactions between three carnivore species in the Romanian Carpathians. Romania houses one of the few intact carnivore guilds in Europe, making it an ideal system to assess intraguild interactions, and serve as a guide for reintroductions elsewhere. 3. We used camera trap data from two seasons in Transylvanian forests to assess occupancy and co-occurrence of carnivores using multispecies occupancy models. 4. Mean occupancy in the study area was highest for lynx ( winter= 0.76 95% CI: 0.42-0.92; autumn= 0.71 CI: 0.38-0.84) and wolf (winter= 0.60 CI: 0.34-0.78; autumn= 0.81 CI: 0.25-0.95) and lowest for wildcat (winter= 0.40 CI: 0.19-0.63; autumn= 0.52 CI: 0.17-0.78) 5. We found that marginal occupancy predictors for carnivores varied between seasons. We also found differences in predictors of co-occupancy between seasons for both lynx-wolf and wildcat-wolf co-occupancy. For both seasons, we found that conditional occupancy probabilities of all three species were higher when another species was present. 6. Our results indicate that while there are seasonal differences in predictors of occupancy and co-occupancy of the three species, co-occurrence in our study area is high, and is dependent on the existence of continuous, relatively undisturbed forests. 7. Terrestrial carnivore recovery efforts are ongoing worldwide. Insights into interspecific relations between carnivore species are critical when considering the depauperate communities they are introduced in. Our work showcases that apex carnivore coexistence is possible, but dependent on protection afforded to forest habitats and their prey base.
... The economic approach concerning increasing HWI highlights that, in the case of the brown bear, the total number of the animals is much lower than official data. The so-called very high number is used as a cover for authorizing hunting campaigns, where both Romanian and foreign citizens participate [44]. According to Linnell et al. [45], based on the continuous loss and high fragmentation of habitat triggered by the economic and social development of post-socialist Romania, the Carpathian brown bear population was considered a vulnerable species which required strict protection. ...
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Human–wildlife interactions (HWI) were frequent in the post-socialist period in the mountain range of Central European countries where forest habitats suffered transitions into built-up areas. Such is the case of the Upper Prahova Valley from Romania. In our study, we hypothesized that the increasing number of HWI after 1990 could be a potential consequence of woodland loss. The goal of our study was to analyse the effects of landscape changes on HWI. The study consists of the next steps: (i) applying 450 questionnaires to local stakeholders (both citizens and tourists) in order to collect data regarding HWI temporal occurrences and potential triggering factors; (ii) investigating the relation between the two variables through the Canonical Correspondence Analysis (CCA); (iii) modelling the landscape spatial changes between 1990 and 2018 for identifying areas with forest loss; (iv) overlapping the distribution of both the households affected by HWI and areas with loss of forested ecosystems. The local stakeholders indicate that the problematic species are the brown bear (Ursus arctos), the wild boar (Sus scrofa), the red fox (Vulpes vulpes) and the grey wolf (Canis lupus). The number of animal–human interactions recorded an upward trend between 1990 and 2018, and the most significant driving factors were the regulation of hunting practices, the loss of habitats, and artificial feeding. The landscape change analysis reveals that between 1990 and 2018, the forest habitats were replaced by built-up areas primarily on the outskirts of settlements, these areas coinciding with frequent HWI. The results are valid for both forest ecosystems conservation in the region, wildlife management, and human infrastructures durable spatial planning.
... Conversely, positive outcomes may include reduced human-carnivore conflict, given that the exploitation of large carnivores can be associated Conservation Biology Volume 35, No. 4, 2021 with increased levels of subsequent conflict (e.g., Teichmann et al. 2016). Additionally, bans that remove what is often the largest source of adult mortality from carnivore populations (Darimont et al. 2015) may improve population health and resilience, especially if preban quotas are based on overly optimistic population assessments (Popescu et al. 2016;Darimont et al. 2018). More broadly, potentially cascading and interacting effects might be complex in cases in which hunting influences densities, age structures, behaviors, and community interactions. ...
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The social license to operate framework considers how society grants or withholds informal permission for resource extractors to exploit publicly owned resources. We developed a modified model, which we refer to as the social license to hunt (SLH). In it we similarly consider hunters as operators, given that wildlife are legally considered public resources in North America and Europe. We applied the SLH model to examine the controversial hunting of large carnivores, which are frequently killed for trophies. Killing for trophies is widespread, but undertaken by a minority of hunters, and can pose threats to the SLH for trophy-seeking carnivore hunters and potentially beyond. Societal opposition to large carnivore hunting relates not only to conservation concerns but also to misalignment between killing for trophies and dominant public values and attitudes concerning the treatment of animals. We summarized cases related to the killing of grizzly bears (Ursus arctos), wolves (Canis lupus), and other large carnivores in Canada, the United States, and Europe to illustrate how opposition to large carnivore hunting, now expressed primarily on social media, can exert rapid and significant pressure on policy makers and politicians. Evidence of the potential for transformative change to wildlife management and conservation includes proposed and realized changes to legislation, business practice, and wildlife policy, including the banning of some large carnivore hunts. Given that policy is ultimately shaped by societal values and attitudes, research gaps include developing increased insight into public support of various hunting policies beyond that derived from monitoring of social media and public polling. Informed by increased evidence, the SLH model can provide a conceptual foundation for predicting the likelihood of transient versus enduring changes to wildlife conservation policy and practice for a wide variety of taxa and contexts.
... However, moose populations experienced high hunting pressure immediately after 1991, because of government instability and a lack of wildlife protection, resulting in an overharvesting of natural resources 32,33,53 . Political instability may have also influenced data quality because there may have been less oversight and less effort, leading to less reliable information about the status of wildlife population, and ultimately ill-advised management decisions and hunting quotas 54,55 . To reduce the effects of these potential errors, we averaged moose density over time (by decade and for the full study period). ...
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Identifying the factors that determine habitat suitability and hence patterns of wildlife abundances over broad spatial scales is important for conservation. Ecosystem productivity is a key aspect of habitat suitability, especially for large mammals. Our goals were to a) explain patterns of moose (Alces alces) abundance across Russia based on remotely sensed measures of vegetation productivity using Dynamic Habitat Indices (DHIs), and b) examine if patterns of moose abundance and productivity differed before and after the collapse of the Soviet Union. We evaluated the utility of the DHIs using multiple regression models predicting moose abundance by administrative regions. Univariate models of the individual DHIs had lower predictive power than all three combined. The three DHIs together with environmental variables, explained 79% of variation in moose abundance. Interestingly, the predictive power of the models was highest for the 1980s, and decreased for the two subsequent decades. We speculate that the lower predictive power of our environmental variables in the later decades may be due to increasing human influence on moose densities. Overall, we were able to explain patterns in moose abundance in Russia well, which can inform wildlife managers on the long-term patterns of habitat use of the species.
... Moreover, short of establishing population studies within each local area where harvest is increased in response to conflicts, there is no effective means of gauging how much an increased harvest affected population size and trend. Across the range of bears (not just American black bears), it is common that agencies managing harvests lack precise population monitoring tools [12,74,75], and without these, intensive harvests directed at relieving conflicts could be a risky option. ...
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Among the world’s large Carnivores, American black bears (Ursus americanus) are the foremost conservation success story. Populations have been expanding across North America because the species is adaptable and tolerant of living near people, and because management agencies in the U.S. and Canada controlled hunting and other human-sources of mortality. As a result, human–black bear conflicts (damage to property, general nuisance, threat to human safety) have dramatically increased in some areas, making it urgently important to develop and deploy a variety of mitigation tools. Previous studies claimed that legal hunting did not directly reduce conflicts, but they did not evaluate whether hunting controlled conflicts via management of population size. Here, we compared temporal patterns of phoned-in complaints about black bears (total ~63,500) in Minnesota, USA, over 4 decades to corresponding bear population estimates: both doubled during the first decade. We also quantified natural bear foods, and found that large year-to-year fluctuations affected numbers of complaints; however, since this variation is due largely to weather, this factor cannot be managed. Complaints fell sharply when the management agency (1) shifted more responsibility for preventing and mitigating conflicts to the public; and (2) increased hunting pressure to reduce the bear population. This population reduction was more extreme than intended, however, and after hunting pressure was curtailed, population regrowth was slower than anticipated; consequently both population size and complaints remained at relatively low levels statewide for 2 decades (although with local hotspots). These long-term data indicated that conflicts can be kept in tolerable bounds by managing population size through hunting; but due to the bluntness of this instrument and deficiencies and uncertainties in monitoring and manipulating populations, it is wiser to maintain a population at a level where conflicts are socially-acceptable than try to reduce it once it is well beyond that point.
... Institutionalising the data can potentially lead to some extent of misreporting. Hunters might 366 report a higher harvest rate or a higher number of observations to artificially boost population 367 numbers, increasing the quota for the following year (Popescu et al., 2016) or to pretend that 368 they are active on their concession and that they follow the wildlife management plan. This can 369 lead to growing population of game species leading to an increasing human-wildlife interface 370 and resulting in more damages to properties. ...
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Monitoring biodiversity characteristics at large scales and with adequate resolution requires considerable effort and resources. Overall, there is clearly a huge scope for European hunters, a special and often overlooked group of citizen scientist, to contribute even more to biodiversity monitoring, especially because of their presence across the entire European landscape. Using the Essential Biodiversity Variables (EBVs) framework we reviewed the published and grey literature and contacted experts to provide a comprehensive overview of hunters’ contributions to biodiversity monitoring. We examined the methods used to collect data in hunter-based monitoring, the geographic and taxonomic extent of such contributions and the scientific output stemming from hunter-based monitoring data. Our study suggests that hunter-based monitoring is widely distributed across Europe and across taxa as 32 out of the 36 European countries included in our analysis involve hunters in the monitoring of at least one species group with ungulates and small game species groups which have the widest hunter-based monitoring coverage. We found that it is possible to infer characteristics on Genetic composition, Species population, Species traits and Community composition with data that are being routinely collected by hunters in at least some countries. The main types of data provided are hunting bags data, biological samples including carcasses of shot animals and non-invasive samplings and Observations for counts and indices. Hunters collect data on biodiversity in its key dimensions. Collaborations between hunters and scientists are fruitful and should be considered a standard partnership for biodiversity conservation. To overcome the challenges in the use of hunters’ data, more rigorous protocols for sampling data should be implemented and improvements made in data integration methods.
... Institutionalising the data can potentially lead to some extent of misreporting. Hunters might 366 report a higher harvest rate or a higher number of observations to artificially boost population 367 numbers, increasing the quota for the following year (Popescu et al., 2016) or to pretend that 368 they are active on their concession and that they follow the wildlife management plan. This can 369 lead to growing population of game species leading to an increasing human-wildlife interface 370 and resulting in more damages to properties. ...
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1.Monitoring biodiversity characteristics at large scales and with adequate resolution requires considerable effort and resources. Overall, there is clearly a huge scope for European hunters, a special and often overlooked group of citizen scientist, to contribute even more to biodiversity monitoring, especially because of their presence across the entire European landscape.2.Using the Essential Biodiversity Variables (EBVs) framework we reviewed the published and grey literature and contacted experts to provide a comprehensive overview of hunters’ contributions to biodiversity monitoring. We examined the methods used to collect data in hunter-based monitoring, the geographic and taxonomic extent of such contributions and the scientific output stemming from hunter-based monitoring data.3.Our study suggests that hunter-based monitoring is widely distributed across Europe and across taxa as 32 out of the 36 European countries included in our analysis involve hunters in the monitoring of at least one species group with ungulates and small game species groups which have the widest hunter-based monitoring coverage. We found that it is possible to infer characteristics on Genetic composition, Species population, Species traits and Community composition with data that are being routinely collected by hunters in at least some countries. The main types of data provided are hunting bags data, Biological samples including carcasses of shot animals and non-invasive samplings and observations for counts and indices.4.Hunters collect data on biodiversity in its key dimensions, collaborations between hunters and scientists are fruitful and should be considered a standard partnership for biodiversity conservation. To overcome the challenges in the use of hunters’ data, more rigorous protocols for sampling data should be implemented and improvements made in data integration methods.
... A multitude of factors and pathways potentially affect long-term viability, demographic trends, and range occupancy of moose. The functional pathways of drivers of population change occur at spatial and temporal scales that affect habitat suitability (Karns 1998, van Beest and Milner 2013, Monteith et al. 2015, habitat selection (Schwab and Pitt 1991, Fahrig and Rytwinski 2009, Herfindal et al. 2009, Bjorneraas et al. 2012, Van Beest et al. 2012, population demography (Murray et al. 2006, Brown 2011), abundance (Van Ballenberghe 1983, Timmermann 1992, Sylvén 2003, mortality risk (Hebblewhite 2008, Laurian et al. 2008, Wasser et al. 2011), behaviour patterns (Dussault et al. 2004, Bjorneraas et al. 2011, Broders et al. 2012, Street et al. 2015, fitness (Renecker and Hudson 1990, Crichton 1992, Wilton 1992, Lowe et al. 2010, McCann et al. 2013, predator-prey dynamics (Stewart et al. 1985, Messier 1994, Rayl et al. 2015, pathogen burdens (Murray et al. 2006, Lenarz et al. 2009, Doak and Morris 2010, and population viability (Popescu et al. 2016). Although there is a paucity of empirical data to quantify the relative effects of these drivers of population change (e.g., comprehensive hunter harvest statistics) in the Boreal Plain Ecozone, there are common probable causes of moose population decline (Table 1). ...
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Broad scale analyses of winter population survey data collected between 1985 and 2015 were conducted to provide a synthesis of the current status and historical performance of 14 moose (Alces alces) populations residing in the Boreal Plain Ecozone of Saskatchewan and western Manitoba. Population time series models indicated a broad scale decline averaging 30% in moose populations across the Boreal Plain Ecozone since 2000 relative to the long-term (1985 to 2015) cumulative mean population size. Demographic patterns and rates of population change were variable among and within populations across years. We found an inverse relationship between adult sex ratio (bull:cow) and population density (R² = 0.48, P < 0.001), which suggests negative population growth (λ < 1.0) when the adult sex ratio falls below a density-dependent threshold of population growth. Winter calf recruitment (calves/cow) was positively correlated (R² = 0.12, P = 0.027) with adult sex ratio. Stable or increasing populations (λ ≥ 1.0) tended to have lower adult sex ratios relative to winter calf recruitment ratios than declining populations. Population state and vital rate relationships are useful to assess population performance and guide science-based moose management strategies in a Management-by-Objective decision-analytic framework.
Article
Conservation conflicts are gaining importance in contemporary conservation scholarship such that conservation may have entered a conflict hype. We attempted to uncover and deconstruct the normative assumptions behind such studies by raising several questions: what are conservation conflicts, what justifies the attention they receive, do conservation-conflict studies limit wildlife conservation, is scientific knowledge stacked against wildlife in conservation conflicts, do conservation-conflict studies adopt a specific view of democracy, can laws be used to force conservation outcomes, why is flexibility needed in managing conservation conflicts, can conservation conflicts be managed by promoting tolerance, and who needs to compromise in conservation conflicts? We suggest that many of the intellectual premises in the field may defang conservation and prevent it from truly addressing the current conservation crisis as it accelerates. By framing conservation conflicts as conflicts between people about wildlife or nature, the field insidiously transfers guilt, whereby human activities are no longer blamed for causing species decline and extinctions but conservation is instead blamed for causing social conflicts. When the focus is on mitigating social conflicts without limiting in any powerful way human activities damaging to nature, conservation-conflict studies risk keeping conservation within the limits of human activities, instead of keeping human activities within the limits of nature. For conservation to successfully stop the biodiversity crisis, we suggest the alternative goal of recognizing nature's right to existence to maintenance of ecological functions and evolutionary processes. Nature being a rights bearer or legal person would imply its needs must be explicitly taken into account in conflict adjudication. If, even in conservation, nature's interests come second to human interests, it may be no surprise that conservation cannot succeed.
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Habitat characteristics associated with species occurrences represent important baseline information for wildlife management and conservation, but have rarely been assessed for countries recently joining the EU. We used footprint tracking data and landscape characteristics in Romania to investigate the occurrence of brown bear (Ursus arctos), gray wolf (Canis lupus) and Eurasian lynx (Lynx lynx) and to compare model predictions between Natura 2000 and national-level protected areas (gap analysis). Wolves were more likely to occur where rugged terrain was present. Increasing proportion of forest was positively associated with occurrence of all large carnivores, but forest type (broadleaf, mixed, or conifer) generally varied with carnivore species. Areas where cultivated lands were extensive had little suitable habitat for lynx, whereas bear occurrence probability decreased with increasing proportion of built areas. Pastures were positively associated with wolf and lynx occurrence. Brown bears occurred primarily where national roads with high traffic volumes were at low density, while bears and lynx occurred at medium-high densities of communal roads that had lower traffic volumes. Based on predictions of carnivore distributions, natural areas protected in national parks were most suitable for carnivores, nature parks were less suitable, whereas EU-legislated Natura 2000 sites had the lowest probability of carnivore presence. Our spatially explicit carnivore habitat suitability predictions can be used by managers to amend borders of existing sites, delineate new protected areas, and establish corridors for ecological connectivity. To assist recovery and recolonization, management could also focus on habitat predicted to be suitable but where carnivores were not tracked.
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Population density data on depleted and endangered wildlife species are essential to assure their effective management and, ultimately, conservation. The European wildcat is an elusive and threatened species inhabiting the Iberian Peninsula, with fragmented populations and living in low densities. We fitted spatial capture–recapture models on camera‐trap data, to provide the first estimate of wildcat density for Portugal and assess the most influential drivers determining it. The study was implemented in Montesinho Natural Park (NE Portugal), where we identified nine individuals, over a total effort of 3,477 trap‐nights. The mean density estimate was 0.032 ± 0.012 wildcat/km2, and density tended to increase with distance to humanized areas, often linked to lower human disturbance and domestic cat presence, with forest and herbaceous vegetation cover and with European rabbit abundance. Although, this density estimate is within the range of values estimated for protected areas elsewhere in the Iberian Peninsula, our estimates are low at the European level. When put in context, our results highlight that European wildcats may be living in low population densities across the Iberian Mediterranean biogeographic region. No phenotypic domestic or hybrid cats were detected, suggesting potentially low admixture rates between the two species, although genetic sampling would be required to corroborate this assertion. We provide evidence that Montesinho Natural Park may be a suitable area to host a healthy wildcat population, and thus be an important protected area in this species' conservation context. We fitted spatial capture–recapture models on European wildcat camera‐trap data to provide the first estimate of wildcat density for Portugal (Western Europe). Mean density was 0.032 ± 0.012 wildcat/km2 and increased with distance to humanized areas, with European rabbit abundance and with forest and herbaceous vegetation cover. Our estimates are low at the European level and highlight that European wildcats may be living at low population densities across the Iberian Mediterranean biogeographic region.
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Forests are a unique environmental phenomenon, since their space serves as the fundamental basis for the life of an innumerable number of biological species. Significant integral limited territories of forests are important ecosystems of our planet and have a significant impact on climate and biological processes. Mixed or single-breed, mountain or plain, dense or well-groomed, the forest as a self-regulating system with its life cycle is directly related to the natural balance. Currently, fragmentation, degradation and loss of natural habitats of animals are recognized as serious threats to the conservation of wildlife around the world. First of all, these changes are anthropogenic in nature and directly affect forests as a sphere of existence of the animal world. This issue is updated in the works of modern domestic and foreign scientists. Fragmentation, deterioration, and destruction of natural animal habitats are major threats to global wildlife conservation. The article introduces some results of monitoring the existing data on the layout chart, exportation, and protection of hunting grounds on the territory of the Kemerovo region (Kuzbass). The data were provided by the Kemerovo Regional Department of Wildlife Protection. The article focuses on the population of large game species, e.g. elks. The research covered two municipalities, namely Krapivinsky and Topkinsky municipal districts. The study proved that monitoring data analysis can provide reliable initial assessment of the changes that happen to the hunting grounds and the local biodiversity as a result of natural and man-induced processes. A comparative analysis of game population in several economic zones of the Kemerovo region revealed a strong connection between the uneven growth and / or decrease in the animal population on the hunting grounds and the level of forest coverage. Based on the study of monitoring data, analysis of comparative material on the number of hunting species in different economic zones of the Kemerovo region revealed the existence of natural connections between uneven growth and/or reducing the number of animals on the hunting grounds, and’s forest coverage rate. The study confirms and complements the research of Russian and foreign researchers on the complex influence of anthropogenic and biological factors on changes in the parameters of the population of hunting species (elk). The obtained results contribute to modern research on the mechanisms of population regulation. To improve the efficiency of hunting resources use, it is necessary to conduct on-farm management with the introduction of new methods of land quality assessment based on forest management materials in geoinformation systems. These points fit into the prospects of our further research.
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Article impact statement: Reporting of population data and associated policies are prone to political influence.
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La Cordillera de los Cárpatos en Rumania constituye un área prioritaria para la conservación del oso pardo (Ursus arctos L.) en el territorio europeo, ya que presenta grandes extensiones de hábitat para la especie con un alto grado de continuidad. No obstante, sin acciones responsables por parte de los gobernantes, los futuros proyectos de desarrollo localizados en este territorio representan una amenaza para la conectividad y la disponibilidad de hábitat de la especie. Se presenta, por tanto, la necesidad de identificar las zonas preferentes de paso para la especie con el fin de definir y proteger una red ecológica resiliente que garantice la conectividad entre las poblaciones que habitan en el territorio. Concretamente, este estudio compara diferentes enfoques de modelización con el fin de identificar los corredores y áreas prioritarias para la conectividad del oso pardo a lo largo de la región sudeste de los Cárpatos. Para ello, primero se elaboraron diferentes mapas de resistencia en base a modelos de disponibilidad de hábitat (MaxEnt) y conocimiento experto. Posteriormente, se estimaron las distancias de mínimo coste (Linkage Mapper) y se aplicó teoría de circuitos (Circuitscape), para definir los principales corredores utilizados por la especie. Finalmente, se evaluó la importancia contribución de cada uno de los elementos identificados que conforman la red ecológica (Conefor 2.6). Este estudio proporciona nuevas conclusiones relacionadas con la aplicación de diferentes enfoques conceptuales de modelización de la conectividad, así como indica las áreas prioritarias a integrar en los futuros planes territoriales y en la gestión de la especie.
Thesis
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In order to protect a species efficiently, measures need to be taken not only towards the species itself, but also towards the habitats where it occurs. We assessed the habitat selection of four large mammals (Ursus arctos, Canis lupus, Lynx lynx and Cervus elaphus) during a study in the Ceahlau National Park, Romania. We conducted transects and camera-trap surveys during October 2019 – March 2020. We analyzed the presence data using the Ecological Niche Factorial Analysis (ENFA), considering as proxies for habitats ten environmental variables. Subsequently, we ran the Monte- Carlo Test to assess whether the species followed a random distribution or not. Finally, we created habitat suitability models with MADIFA. Our main outcomes showed an avoidance of urban, agricultural and steep areas by the four large mammals' species. The brown bear showed no strong selection, apart from the aspect, reporting a random distribution. In contrast, the Eurasian lynx resulted in a strong selection toward broadleaf forests and open areas. The grey wolf and the red deer presence were correlated, both selecting mixed forests and similar altitudinal values. Besides, the wolf selected open areas, while the red deer avoided them. Even if the National Park has a small surface with few suitable areas for large carnivores, their presence was high. Most of the species were detected closer to the limits. Therefore, future inventories and management actions must be addressed toward suitable areas and must include a buffer zone outside the National Park borders. We want to promote the use of pilot studies to minimize the effort and maximize the efficiency of monitoring plans.
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Despite having a large range in the Romanian Carpathians, the ecology of Eurasian lynx is relatively misunderstood, particularly concerning the size of its home range and utilized resources. By means of a collar equipped with a GPS device, the movements of a mature lynx female were monitored for a period of 305 days in the northwestern section of Vrancea Mountains. The area of the female's home range is estimated at 486.11 km2, a significantly larger area than what had been recorded previously for Romania. The probability of lynx occurrence is slightly diminished with each 1% decrease in coniferous forest cover, mixed forest, natural grassland, and shrub cover, and is considerably augmented by increasing spatial heterogeneity. To protect the Romanian lynx population effectively, the application of landscape-scale forestry management strategies is needed, instead of multiple uncorrelated management plans for the different protected areas located in the region.
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During September 1980-December 1986, 81 radio-collared wolves (Canis lupus) were monitored in and near the 839-km2 Bearville Study Area )BSA) in north-central Minnesota. Each year winter-territory size averaged 78-153 km2; no territories had road densities >0.72 km/km2. From zero to 30% of radiomarked pup, yearling, or adult wolves left their territories each month. Pups left natal packs during January-March and older wolves left frequently during September-April. Wolves temporarily leaving territories moved 5-105 km away and were absent 3-118 days; up to 6 exploratory moves were made prior to dispersal. Dispersing wolves traveled 5-100 km away during periods of 1-265 days. One disperser joined and established pack, but 16 others formed new packs. Annual dispersal rates were about 0.17 for adults, 0.49 for yearlings, and 0.10 for pups. Each year mean pack size ranged from 5-9 in November/December to 4-6 in March. Annual wolf density (including 16% lone wolves) ranged from 39-59 wolves/1,000 km2 in November-December and 29-40 wolves/1,000 km2 in March. Annual immigration was 7%. The observed mean annual finite rate of increase was 1.02, and annual rates of increase were correlated with mean number of pups per pack in November. Litters averaged 6.6 pups at birth and 3.2 pups by mid-November, at which time pups made up 46% of pack members. Annual survival of radio-marked wolves >5 months old was 0.64. Despite legal protection, 80% of identified wolf mortality was human caused (30% shot, 12% snared, 11% hit by vehicles, 6% killed by government trappers, and 21% kill by humans in some undetermined manner); 10% of wolves that died were killed by other wolves. During sample periods in 2 winters, wolves were located twice daily to estimate predation rates on white-tailed deer (Odocoileus virginianus). Estimated minimum kill rates during January-February (x = 21 days/kill/wolf) did not differ between winters with differing snow depths. Winter consumption averaged 2.0 kg deer/wolf/day (6% body wt/day). Scat analyses indicated deer were the primary prey in winter and spring, but beaver (Castor canadensis) were an important secondary prey (20-47% of items in scats) during April-May. Neonatal deer fawns occurred in 25-60% of scats during June-July whereas the occurrence of beaver declined markedly. Overall, deer provided 79-98% of biomass consumed each month. Adult wolves consumed an estimated 19/year, of which 11 were fawns. A review of North American studies indicates that wolf numbers are directly related to ungulate biomass. Where deer are primary prey, territory size is related to deer density. Per capita biomass availability likely affects pup survival, the major factor in wolf population growth. Annual rates of increase of exploited populations vary directly with mortality rates, and harvest exceeding 28% of the winter population often result in declines. Management decisions concerning wolf and ungulate density and ungulate harvest by humans can be made using equations that incorporate estimate of wolf density, annual ungulated kill per wolf, ungulate densities, potential rate of increase for ungulates, and harvest.
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1.Reliable assessment of animal populations is a long-standing challenge in wildlife ecology. Technological advances have led to widespread adoption of camera traps (CTs) to survey wildlife distribution, abundance, and behaviour. As for any wildlife survey method, camera trapping must contend with sources of sampling error such as imperfect detection. Early applications focused on density estimation of naturally marked species, but there is growing interest in broad-scale CT surveys of unmarked populations and communities. Nevertheless, inferences based on detection indices are controversial and the suitability of alternatives such as occupancy estimation is debatable.2.We reviewed 266 CT studies published between 2008 and 2013. We recorded study objectives and methodologies, evaluating the consistency of CT protocols and sampling designs, the extent to which CT surveys considered sampling error, and the linkages between analytical assumptions and species ecology.3.Nearly two-thirds of studies surveyed more than one species, and a majority used response variables that ignored imperfect detection (e.g. presence–absence, relative abundance). Many studies used opportunistic sampling and did not explicitly report details of sampling design and camera deployment that could affect conclusions.4.Most studies estimating density used capture-recapture methods on marked species, with spatially explicit methods becoming more prominent. Few studies estimated density for unmarked species, focusing instead on occupancy modelling or measures of relative abundance. While occupancy studies estimated detectability, most did not explicitly define key components of the modelling framework (e.g. a site), or discuss potential violations of model assumptions (e.g. site closure). Studies using relative abundance relied on assumptions of equal detectability, and most did not explicitly define expected relationships between measured responses and underlying ecological processes (e.g. animal abundance and movement).5.Synthesis and applications. The rapid adoption of camera traps represents an exciting transition in wildlife survey methodology. We remain optimistic about the technology's promise, but call for more explicit consideration of underlying processes of animal abundance, movement, and detection by cameras, including more thorough reporting of methodological details and assumptions. Such transparency will facilitate efforts to evaluate and improve the reliability of camera trap surveys, ultimately leading to stronger inferences and helping to meet modern needs for effective ecological inquiry and biodiversity monitoring.This article is protected by copyright. All rights reserved.
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The conservation of large carnivores is a formidable challenge for biodiversity conservation. Using a data set on the past and current status of brown bears (Ursus arctos), Eurasian lynx (Lynx lynx), gray wolves (Canis lupus), and wolverines (Gulo gulo) in European countries, we show that roughly one-third of mainland Europe hosts at least one large carnivore species, with stable or increasing abundance in most cases in 21st-century records. The reasons for this overall conservation success include protective legislation, supportive public opinion, and a variety of practices making coexistence between large carnivores and people possible. The European situation reveals that large carnivores and people can share the same landscape.
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Anecdotal evidence suggests that socioeconomic shocks strongly affect wildlife populations, but quantitative evidence is sparse. The collapse of socialism in Russia in 1991 caused a major socioeconomic shock, including a sharp increase in poverty. Our goal was to analyze population trends of eight large mammals (5 herbivores and 3 carnivores) in Russia from 1981 to 2010, i.e., before and after the collapse. We hypothesized that the collapse would first cause population declines, primarily due to overexploitation, and then population increases due to adaptation of wildlife to new environments following the collapse. The extensive and long-term Database of the Russian Federal Agency of Game Mammal Monitoring, consisting of up to 50,000 transects that are monitored annually, provided an exceptional data set for investigating these population trends. We found that three species showed strong declines in population growth rates in the decade following the collapse, while grey wolf increased by more than 150%. However, after 2000 these trends reversed; for example, roe deer numbers in 2010 were the highest of any period in our study. Likely reasons for the population declines in the 1990s include poaching and the erosion of wildlife protection enforcement. The rapid increase of the grey wolf populations is likely due to the cessation of governmental population control. In general, the widespread declines in wildlife populations after the collapse of the Soviet Union highlight the magnitude of the effects that socioeconomic shocks can have on wildlife populations and the possible need for special conservation efforts during such times.
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There is increasing evidence of indirect effects of hunting on populations. In species with sexually selected infanticide (SSI), hunting may decrease juvenile survival by increasing male turnover. We aimed to evaluate the relative importance of direct and indirect effects of hunting via SSI on the population dynamics of the Scandinavian brown bear (Ursus arctos). We performed prospective and retrospective demographic perturbation analyses for periods with low and high hunting pressures. All demographic rates, except yearling survival, were lower under high hunting pressure, which led to a decline in population growth under high hunting pressure (λ = 0.975; 95% CI = 0.914-1.011). Hunting had negative indirect effects on the population through an increase in SSI, which lowered cub survival and possibly also fecundity rates. Our study suggests that SSI could explain 13.6% of the variation in population growth. Hunting also affected the relative importance of survival and fecundity of adult females for population growth, with fecundity being more important under low hunting pressure and survival more important under high hunting pressure. Our study sheds light on the importance of direct and indirect effects of hunting on population dynamics, and supports the contention that hunting can have indirect negative effects on populations through SSI.
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Between 1990 and 2007, 15 southern white (Ceratotherium simum simum) and black (Diceros bicornis) rhinoceroses on average were killed illegally every year in South Africa. Since 2007 illegal killing of southern white rhinoceros for their horn has escalated to >950 individuals/year in 2013. We conducted an ecological–economic analysis to determine whether a legal trade in southern white rhinoceros horn could facilitate rhinoceros protection. Generalized linear models were used to examine the socioeconomic drivers of poaching, based on data collected from 1990 to 2013, and to project the total number of rhinoceroses likely to be illegally killed from 2014 to 2023. Rhinoceros population dynamics were then modeled under 8 different policy scenarios that could be implemented to control poaching. We also estimated the economic costs and benefits of each scenario under enhanced enforcement only and a legal trade in rhinoceros horn and used a decision support framework to rank the scenarios with the objective of maintaining the rhinoceros population above its current size while generating profit for local stakeholders. The southern white rhinoceros population was predicted to go extinct in the wild <20 years under present management. The optimal scenario to maintain the rhinoceros population above its current size was to provide a medium increase in antipoaching effort and to increase the monetary fine on conviction. Without legalizing the trade, implementing such a scenario would require covering costs equal to approximately $147,000,000/year. With a legal trade in rhinoceros horn, the conservation enterprise could potentially make a profit of $717,000,000/year. We believe the 35-year-old ban on rhinoceros horn products should not be lifted unless the money generated from trade is reinvested in improved protection of the rhinoceros population. Because current protection efforts seem to be failing, it is time to evaluate, discuss, and test alternatives to the present policy. El Grano de los Datos de Costo Económico con Referencia Espacial y de Beneficio a la Biodiversidad y la Efectividad de una Estrategia de Determinación de Costos Resumen Entre 1990 y 2007, en promedio fueron cazados ilegalmente cada año 15 rinocerontes sureños blancos (Ceratotherium simum simum) y negros (Diceros bicornis) en Sudáfrica. Desde 2007 la caza ilegal de rinocerontes sureños blancos por su cuerno ha escalado a más de 950 individuos al año en 2013. Llevamos a cabo un análisis ecológico-económico para determinar si el comercio legal de cuerno de rinoceronte sureño blanco podría facilitar la protección del rinoceronte. Se usaron modelos lineales generalizados para examinar a los conductores socio-económicos de la caza furtiva, con base en datos colectados desde 1990 hasta 2013, y también para proyectar el número total de rinocerontes con probabilidad de ser cazados ilegalmente desde 2014 hasta 2023. Las dinámicas poblacionales de los rinocerontes fueron entonces modeladas bajo ocho escenarios políticos diferentes que podrían implementarse para controlar la caza furtiva. También estimamos los costos económicos y los beneficios de cada escenario solamente bajo la ejecución aumentada del plan de manejo y el comercio legal de cuerno de rinoceronte y usamos un marco de trabajo de apoyo a decisiones para ordenar los escenarios con el objetivo de mantener la población de rinocerontes por encima de su tamaño actual mientras se generan ganancias para los accionistas locales. Se predijo que la población de rinocerontes sureños blancos se extinguiría en menos de 20 años bajo el manejo actual. El escenario óptimo para mantener la población de rinocerontes por encima de su tamaño actual fue el de proporcionar un incremento mediano en el esfuerzo contra la caza furtiva e incrementar la multa monetaria de la condena. Sin legalizar el mercado, implementar tal escenario requeriría cubrir costos de aproximadamente $147, 000, 000 al año. Con un comercio legal de cuerno de rinoceronte, la iniciativa de conservación podría ganar potencialmente $717, 000, 000 al año. Creemos que la prohibición de 35 años de los productos de cuerno de rinoceronte no debería ser levantada a menos que el dinero generado de este comercio sea reinvertido en la protección mejorada de la población de rinocerontes. Ya que los esfuerzos de protección actuales parecen estar fallando, es momento de evaluar, discutir y probar alternativas a la política actual.
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We analysed yearly estimates of population size data during 2001-2012 for five carnivores species of conservation interest (Ursus arctos, Canis lupus, Lynx lynx, Felis silvestris and Canis aureus). Population size estimations were done by the game management authorities and integrated by the competent authorities on the Ministry of Environment and Climate Change. Trends in data were detected using non-parametric Mann-Kendall test. This test was chosen considering the short length of data series and its usefulness for non-normal distributed data. The trend was tested at three spatial scales: game management units (n=1565), biogeographical region (n=5) and national. Trends depicted for each game management unit were plotted using ArcGIS, resulting species trend distribution maps. For the studied period increasing population trends were observed for Ursus arctos, Canis lupus, Canis aureus and Lynx lynx, while for Felis silvestris there was no trend recorded. Such an analysis in especially useful for conservation proposes, game management and reporting obligations under article 17 of the EC Habitat Directive, using population trend as a proxy for population dynamics. We conclude that the status of the five carnivore species is favourable during the study period.
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In December 2013, the provincial government of British Columbia, Canada, approved the expansion of a controversial trophy hunt of at-risk grizzly bears. This decision raises doubts about the rigor of wildlife management and government policy in the region.
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Large carnivores face serious threats and are experiencing massive declines in their populations and geographic ranges around the world. We highlight how these threats have affected the conservation status and ecological functioning of the 31 largest mammalian carnivores on Earth. Consistent with theory, empirical studies increasingly show that large carnivores have substantial effects on the structure and function of diverse ecosystems. Significant cascading trophic interactions, mediated by their prey or sympatric mesopredators, arise when some of these carnivores are extirpated from or repatriated to ecosystems. Unexpected effects of trophic cascades on various taxa and processes include changes to bird, mammal, invertebrate, and herpetofauna abundance or richness; subsidies to scavengers; altered disease dynamics; carbon sequestration; modified stream morphology; and crop damage. Promoting tolerance and coexistence with large carnivores is a crucial societal challenge that will ultimately determine the fate of Earth’s largest carnivores and all that depends upon them, including humans.
Technical Report
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Large carnivores (bears Ursus arctos, wolves Canis lupus, lynx Lynx lynx and wolverines Gulo gulo) are among the most challenging group of species to maintain as large and continuous populations or to reintegrate back into the European landscape. Political, socioeconomic and society changes challenge past management approaches in some of the large populations. At the same time local improvements in habitat quality, the return of their prey species, public support and favourable legislation allow for the recovery of some small populations. Several of Europe’s large carnivore populations are large and robust, others are expanding, some small populations remain critically endangered and a few are declining. Large carnivores need very large areas and their conservation needs to be planned on very wide spatial scales that will often span many intra‐ and inter‐national borders. Within these large scales conservation and management actions need to be coordinated. To facilitate coordination, a common understanding of the present day conservation status of large carnivores at national and population level is an important basis. The aim of this summary report is to provide an expert based update of the conservation status of all populations identified by the Large Carnivore Initiative for Europe (LCIE), available in the document “Guidelines for Population Level Management Plans for Large Carnivores” (Linnell et al. 2008) and/or in the various Species Online Information Systems (http://www.kora.ch/sp‐ois/; also see Appendix 1). However, methods used to monitor large carnivores vary and a direct comparison over time or among populations will never be possible at a continental scale. It is more realistic to have an insight into the general order of magnitude of the population, its trend and permanent range as the “currencies” for comparisons and assessments (see point 2). This summary also does not aim to replace the habitat directive reporting, but rather complement it. Discrepancies will likely occur due to different time periods covered and different agreements reached on common reporting criteria on a national level which has to deal with many more species. Furthermore, for several countries the most recent data or distribution map were not always available, yet. Changes in monitoring methods likely result in changing population estimates, even in stable populations. Improved and more costly methods may suddenly discover that previous estimates were too high, or may detect more individuals than previously assumed. Examples of both occur. Being aware of the change in methodology the expert assessment may still be “stable” for the population even if numbers listed in tables have changed. On the other hand, large scale “official” (government) estimates may be based on questionable or non‐transparent extrapolations that run contrary to data from reference areas within the country or similar regions from other countries. If the discrepancy is apparent, expert assessment needs to question official numbers. This summary does not aim at reviewing monitoring techniques. Examples of parameters and principles for monitoring large carnivores and some “good practice” examples have been previously compiled by the LCIE (http://www.lcie.org/Docs/LCIE%20IUCN/LCIE_PSS_monitoring.pdf). Furthermore, references at the end of many country reports do provide ample examples of well documented and state of the art monitoring of large carnivores in Europe under a wide variety of different contexts.
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Sustainable management of terrestrial hunting requires managers to set quotas restricting offtake. This often takes place in the absence of reliable information on the population size, and as a consequence, quotas are set in an arbitrary fashion, leading to population decline and revenue loss. In this investigation, we show how an indirect measure of abundance can be used to set quotas in a sustainable manner, even in the absence of information on population size. Focusing on lion hunting in Africa, we developed a simple algorithm to convert changes in the number of safari days required to kill a lion into a quota for the following year. This was tested against a simulation model of population dynamics, accounting for uncertainties in demography, observation, and implementation. Results showed it to reliably set sustainable quotas despite these uncertainties, providing a robust foundation for the conservation of hunted species.
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Scientific management of wildlife requires confronting the complexities of natural and social systems. Uncertainty poses a central problem. Whereas the importance of considering uncertainty has been widely discussed, studies of the effects of unaddressed uncertainty on real management systems have been rare. We examined the effects of outcome uncertainty and components of biological uncertainty on hunt management performance, illustrated with grizzly bears (Ursus arctos horribilis) in British Columbia, Canada. We found that both forms of uncertainty can have serious impacts on management performance. Outcome uncertainty alone - discrepancy between expected and realized mortality levels - led to excess mortality in 19% of cases (population-years) examined. Accounting for uncertainty around estimated biological parameters (i.e., biological uncertainty) revealed that excess mortality might have occurred in up to 70% of cases. We offer a general method for identifying targets for exploited species that incorporates uncertainty and maintains the probability of exceeding mortality limits below specified thresholds. Setting targets in our focal system using this method at thresholds of 25% and 5% probability of overmortality would require average target mortality reductions of 47% and 81%, respectively. Application of our transparent and generalizable framework to this or other systems could improve management performance in the presence of uncertainty.
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Naturally dynamic forests have a high proportion of biotopes with old large trees, diverse vertical and horizontal structure at multiple scales, and much dead wood. As such, they provide habitat to species and ecosystem processes that forests managed for wood production cannot provide to the same degree. Whether termed old-growth, ancient, virgin, intact, primeval or continuity forests, a major challenge and need is to map such potential high conservation value forest for subsequent inclusion in functional habitat networks for biodiversity conservation in forest landscapes. Given that the delivery time of natural forest properties is much longer than of industry wood, we explore the usefulness of using historical maps to identify forests that have been continuously present for 220 years (potential old-growth) versus 140 years (potential aging forest) in a case study in the Romanian Carpathian Mountains (see Online Resource 1). While the total forest cover increased by 35 % over the past two centuries, the area of potential aging and potential old-growth forest declined by 56 and 34 %, respectively. Spatial modelling of edge effects and patch size for virtual species with different requirements indicated an even greater decrease in the area of functional habitat networks of old-growth and ageing forest. Our analyses show that compared to simple mapping of potential high conservation forests, the area of functional habitat patches is severely overestimated, and caution is needed when estimating the area of potential high conservation value forests that form functional habitat networks, i.e. a green infrastructure. In addition, the landscape and regional scale connectivity of patches needs to be considered. We argue that the use of historical maps combined with assessment of spatial patterns is an effective tool for identifying and analyzing potential high conservation value forests in a landscape context.
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Reliable analyses can help wildlife managers make good decisions, which are particularly critical for controversial decisions such as wolf (Canis lupus) harvest. Creel and Rotella (2010) recently predicted substantial population declines in Montana wolf populations due to harvest, in contrast to predictions made by Montana Fish, Wildlife and Parks (MFWP). We replicated their analyses considering only those years in which field monitoring was consistent, and we considered the effect of annual variation in recruitment on wolf population growth. Rather than assuming constant rates, we used model selection methods to evaluate and incorporate models of factors driving recruitment and human-caused mortality rates in wolf populations in the Northern Rocky Mountains. Using data from 27 area-years of intensive wolf monitoring, we show that variation in both recruitment and human-caused mortality affect annual wolf population growth rates and that human-caused mortality rates have increased with the sizes of wolf populations. We document that recruitment rates have decreased over time, and we speculate that rates have decreased with increasing population sizes and/or that the ability of current field resources to document recruitment rates has recently become less successful as the number of wolves in the region has increased. Estimates of positive wolf population growth in Montana from our top models are consistent with field observations and estimates previously made by MFWP for 2008–2010, whereas the predictions for declining wolf populations of Creel and Rotella (2010) are not. Familiarity with limitations of raw data, obtained first-hand or through consultation with scientists who collected the data, helps generate more reliable inferences and conclusions in analyses of publicly available datasets. Additionally, development of efficient monitoring methods for wolves is a pressing need, so that analyses such as ours will be possible in future years when fewer resources will be available for monitoring. ß 2011 The Wildlife Society.
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Estimating population size and trends are key issues in the conservation and management of large carnivores. The rebounding brown bear Ursus arctos population in Sweden is monitored by two different systems, both relying on voluntary resources. Population estimates have been calculated using Capture-Mark-Recapture methods, based on DNA-based scat surveys in five of the six Swedish counties with established bear populations. A total of 1,358 genotypes were identified using DNA extracted from collected scats. An independent ongoing programme, the Large Carnivore Observation Index (LCOI), was initiated in 1998. The LCOI uses effort-corrected observations of bears by moose Alces alces hunters during the moose hunt (> 2 million observation hours/year) and has shown a good correlation with relative population density of bears using the DNA-based method. From this, we have calculated population trends during the period 1998-2007. Using an exponential model, we estimated the yearly increase in the bear population to be 4.5% at the national level, varying between 0 and 10.2% in different counties. We used the regional population estimates and the trends from the LCOI, taking the variation from both systems into account using parametric bootstrapping, to calculate the regional as well as the national population size in Sweden in fall 2008. In one case (the northernmost county; Norrbotten) a DNA-scat survey was lacking, so we used assumptions based on data from the neighbouring county to estimate population size. We estimated the Swedish brown bear population to be 3,298 individuals (2,968-3,667; 95% confidence intervals) in 2008. Our results suggest that reliable information, necessary for the management of the brown bear population can be obtained from volunteers using standardised methods.
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Conservation shortcuts such as umbrella species have been long used for regional protection of species whose distributions are poorly known. Although the European large carnivores—brown bear, gray wolf, and Eurasian lynx—might seem to be robust candidates as umbrella species, their actual effectiveness has been challenged. We used 10-km resolution distribution maps of mammals (n=10) and birds (n=55) of European conservation concern in the Romanian Carpathians, and a temporal sequence of land cover maps (1990, 2000, and 2006) to examine: (1) the spatial overlap in distribution between large carnivores and bird and mammal species of conservation concern, (2) changes in forest cover for the Romanian Carpathians during the post-communist period in relation to the distribution of species, and (3) priority conservation areas using carnivores as umbrella species. Approximately 55% of the bird and 80% of mammals species included in this study would potentially benefit from using large carnivores as conservation surrogates. The changes in forest cover during 1990–2006 were concentrated in the Eastern Carpathians, where up to 45% of the forest per mapping unit was clearcut during the study period. Implicitly, the areas of occupancy of the background species were most disturbed by clearcutting in the Eastern Carpathians. We propose that the large carnivores could act temporary as umbrella species in areas that are still relatively undisturbed, such as Southern and Southwestern Carpathians. This alternative conservation strategy will allow time for (1) the new established protected areas to start efficiently and (2) the forestry practices to switch from mostly uncontrolled clearcutting, lacking landscape scale management to ecologically-based practices. KeywordsLarge carnivores–Romanian Carpathians–Umbrella species–Protected areas–Clearcutting–Species of conservation concern
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We apply an age- and stage-structured model incorporating varying harem sizes, paternal care and infanticide to examine the effect of hunting on sustainability of populations. Compared to standard carnivore and herbivore models, these models produce different outcomes for sustainable offtake when either adults, or adult males are harvested. Larger harem size increases sustainable offtake whereas paternal care and infanticide lowers it. Where males are monogamous, populations are vulnerable to male offtake, regardless of paternal care. Surprisingly, an incidental take of 10% of other age–sex-classes has very little effect on these findings. Indiscriminate (subsistence) hunting of all age–sex classes has a dramatic effect on certain populations. Applying these behavior–sensitive models to tourist hunting in the Selous Game Reserve, Tanzania, we find that across the Reserve hunting quotas were generally set at sustainable rates except for leopard (Panthera pardus). In certain hunting blocks within the Reserve, however, quotas for eland (Taurotragus oryx), hartebeest (Alcelaphus buselaphus), lion (Panthera leo), reedbuck (Redunca arundinum), sable antelope (Hippotragus niger), warthog (Phacochoerus aethiopicus) and waterbuck (Kobus ellipsiprymnus) are set at unsustainably high rates. Moreover, particular blocks are consistently awarded high quotas. Behaviorally sensitive models refine predictions for population viability, specify data required to make predictions robust, and demonstrate the necessity of incorporating behavioral ecological knowledge in conservation and management.
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Causes of mortality were described for 245 radio-marked Eurasian lynx (Lynx lynx) in five different Scandinavian study areas. Furthermore, the survival rates and the population growth rates were estimated for three of the study areas where 202 lynx were followed for a total of 314 radio-years. The main causes of mortality in adult Eurasian lynx in all our study areas were overwhelmingly anthropogenic, with starvation, vehicle collisions, intra- and interspecific killing and disease only having a minor role. The mean mortality rates for adults increased from 2% to 17% when hunting and poaching were included, i.e., an increase by a factor of eight. This in turn had a large impact on population growth rates, which changed from more than a 20% annual increase to only a 2–4% when hunting and poaching were included. Poaching accounted for 46% of the mortality in adult lynx. Poaching and legal harvest appear to be primarily motivated by conflicts; lynx depredation on semi-domestic reindeer in northern Scandinavia, competition with hunters for roe deer in southern Scandinavia, and depredation on free-ranging domestic sheep in all Norway. The lowest poaching rate was found in the Hedmark study area in Norway, which also had a high legal harvest. The poaching rate was higher in one of the Swedish study areas (Sarek) where legal hunting was lower than in other areas. On the other hand, both the poaching rate and the legal harvest were high in the Akershus/Østfold study area in Norway. Thus, there does not seem to be a simple relationship between an increased legal harvest and decreased poaching as is commonly expected. The most important conservation actions are to combat poaching through both law enforcement and measures designed to increase tolerance.
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Recent studies indicate that trophy hunting is impacting negatively on some lion populations, notably in Tanzania. In 2004 there was a proposal to list lions on CITES Appendix I and in 2011 animal-welfare groups petitioned the United States government to list lions as endangered under their Endangered Species Act. Such listings would likely curtail the trophy hunting of lions by limiting the import of lion trophies. Concurrent efforts are underway to encourage the European Union to ban lion trophy imports. We assessed the significance of lions to the financial viability of trophy hunting across five countries to help determine the financial impact and advisability of the proposed trade restrictions. Lion hunts attract the highest mean prices (US$24,000-US$71,000) of all trophy species. Lions generate 5-17% of gross trophy hunting income on national levels, the proportional significance highest in Mozambique, Tanzania, and Zambia. If lion hunting was effectively precluded, trophy hunting could potentially become financially unviable across at least 59,538 km(2) that could result in a concomitant loss of habitat. However, the loss of lion hunting could have other potentially broader negative impacts including reduction of competitiveness of wildlife-based land uses relative to ecologically unfavourable alternatives. Restrictions on lion hunting may also reduce tolerance for the species among communities where local people benefit from trophy hunting, and may reduce funds available for anti-poaching. If lion off-takes were reduced to recommended maximums (0.5/1000 km(2)), the loss of viability and reduction in profitability would be much lower than if lion hunting was stopped altogether (7,005 km(2)). We recommend that interventions focus on reducing off-takes to sustainable levels, implementing age-based regulations and improving governance of trophy hunting. Such measures could ensure sustainability, while retaining incentives for the conservation of lions and their habitat from hunting.
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Poaching is a widespread and well-appreciated problem for the conservation of many threatened species. Because poaching is illegal, there is strong incentive for poachers to conceal their activities, and consequently, little data on the effects of poaching on population dynamics are available. Quantifying poaching mortality should be a required knowledge when developing conservation plans for endangered species but is hampered by methodological challenges. We show that rigorous estimates of the effects of poaching relative to other sources of mortality can be obtained with a hierarchical state-space model combined with multiple sources of data. Using the Scandinavian wolf (Canis lupus) population as an illustrative example, we show that poaching accounted for approximately half of total mortality and more than two-thirds of total poaching remained undetected by conventional methods, a source of mortality we term as 'cryptic poaching'. Our simulations suggest that without poaching during the past decade, the population would have been almost four times as large in 2009. Such a severe impact of poaching on population recovery may be widespread among large carnivores. We believe that conservation strategies for large carnivores considering only observed data may not be adequate and should be revised by including and quantifying cryptic poaching.
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On 1 and 2 June 2010, an international meeting was held at the University of Paris Sud XI, France, organized within the framework of the EU FP7 consortium project HUNT, to bring together fisheries and conservation scientists to discuss a unified framework for the future of management strategies for harvested species.
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Reliable population and density estimates are the cornerstone of effective conservation and management planning, as conservation priorities often arise in relation to population numbers. Despite increased public interest and costly conservation programs limited information on brown bear (Ursus arctos, Linnaeus, 1758) abundance and density in Greece exists. We carried out systematic non-invasive genetic sampling using hair traps on power poles, as part of a capture-mark-recapture study design in order to rigorously estimate abundance and density of the Pindos bear population in Greece. From 2007–2010 we identified 211 and estimated a mean of 182.3 individuals in four sampling areas; bear densities ranged from 10.0 to 54 bears/1000 km 2. These results indicate an important population recovery of this large carnivore in Greece in recent years; a conservative population estimate would place the population size in the entire country >450 individuals. Considering the results of the study and the increased negative interactions between humans and bears recorded currently in Greece, we suggest that systematic genetic monitoring using power poles should continue in order to collect the necessary information that will enable the definition of an effective Action Plan for the long-term conservation of this species.
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Trends of grizzly bear (Ursus arctos) populations are most sensitive to female survival; thus, understanding rates and causes of grizzly bear mortality is critical for their conservation. Survival rates were estimated and causes of mortalities investigated for 388 grizzly bears radiocollared for research purposes in 13 study areas in the Rocky and Columbia mountains of Alberta, British Columbia, Montana, Idaho, and Washington between 1975 and 1997. People killed 77-85% of the 99 grizzly bears known or suspected to have died while they were radiocollared. In jurisdictions that permitted grizzly bear hunting, legal harvest accounted for 39-44% of the mortalities. Other major causes of mortality included control killing for being close to human habitation or property, self-defense, and malicious killings. The mortality rate due to hunting was higher (P = 0.006) for males than females, and subadult males had a higher probability (P = 0.007) of being killed as problem animals than did adult males or females. Adult females had a higher (P = 0.009) mortality rate from natural causes than males. Annual survival rates of subadult males (0.74-0.81) were less than other sex-age classes. Adult male survival rates varied between 0.84 and 0.89 in most areas. Survival of females appeared highest (0.95-0.96) in 2 areas dominated by multiple-use land and were lower (0.91) in an area dominated by parks, although few bears were killed within park boundaries. Without radiotelemetry, management agencies would have been unaware of about half (46-51%) of the deaths of radiocollared grizzly bears. The importance of well-managed multiple-use land to grizzly bear conservation should be recognized, and land-use plans for these areas should ensure no human settlement and low levels of recreational activity.
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Black bear (Ursus americanus) damage to managed conifer stands during the spring in the U.S. Pacific Northwest is a continuing management concern. Because bear damage to managed conifers may reflect the limited availability of nutritious foods, supplemental feeding has been used to decrease damage. Highly palatable, pelleted feed is provided ad libitum from April until late June when berries ripen and such damage stops. We examined black bear use of supplemental feed during the spring and summer of 1998 and 1999 in western Washington. Bears were captured in areas where supplemental feed was provided and in control areas where no effort to reduce conifer damage occurred. Mass gains for bears captured twice were 153 ± 119 g/day (x̄ ± SD) in the fed areas and 12 ± 104 g/day in non-fed areas. Fat gain for bears in the fed areas was 42 ± 50 g/day and 4 ± 59 g/day in the non-fed areas. However, because age-specific body masses and fat content did not differ between the 2 areas, short-term pellet feeding probably has no long-lasting effect on bear condition or productivity. The diet of bears in the fed areas was 55 ± 22% pelleted feed, 7 ± 7% animal matter, and 38 ± 18% vegetation. The diet of bears in the non-fed areas was 13 ± 17% animal matter and 87 ± 17% vegetation. Grass and sedge composed the majority of vegetation consumed in both areas. The energy content of Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) sapwood was more digestible (60-67%) than grasses and forbs (18-47%). Smaller bears (adult females and subadult males and females) may do most of the damage because sapwood harvesting rates minimize nutritional gain to larger adult males.
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Breeding populations of wolves (Canis lupus) were absent from the western United States for about 50 years following their extirpation by humans in the 1930s. Here we describe the recolonization by wolves of northwestern Montana and southeastern British Columbia, from the initial production of a litter by a pair of wolves in 1982 through the mid-1990s when 3-4 packs produced litters. Sex ratio of captured wolves favored females (38/54 = 70%; χ 2 = 8.96, 1 df, P < 0.005). Litter size in early summer (x̄ = 5.3, SE = 0.4, n = 26) and in December (x̄ = 4.5, SE = 0.5, n = 26) were relatively high compared to similar counts in established populations elsewhere. Pack size in May was unrelated to litter size in June (rs = -0.13, 23 df, P = 0.25) or the following December (rs = -0.12, 23 df, P = 0.28). Annual adult survival rate (0.80) was relatively high in this semi-protected population and was higher among residents (0.84) than among wolves that dispersed (0.66) from the study area (Z = 2.24, P = 0.025). Although dispersal was common among radiocollared wolves (19/43 = 44%), population growth within the study area averaged 20% per year from 1982 to 1995. Low human-caused mortality rates and maintenance of connectivity for wolves between this small population in the United States and larger populations in Canada will enhance the probability of persistence and expansion of this population.
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The density of adult (≥3 years) female brown bears Ursus arctos was estimated in two areas of Sweden from ratios of radio-marked and unmarked females consorting with radio-marked adult males during the breeding season. The resulting densities were 1·2 ± 0·81 (95% confidence interval) adult females/1000 km2 in a northern study area and 1·06 ± 3·44 adult females/1000 km2 in a southern area. These estimates were extrapolated to obtain a population estimate for Sweden using relative densities throughout the range of the species in Sweden, based on hunter-kill statistics, and observed rates of reproduction and juvenile and subadult survival. The total population in spring 1991 was estimated to be about 620 bears, with almost all females confined to four geographically separated areas, termed female core areas. A supplementary estimate, based on estimated kill rates of adult females in the study areas, was about 660 bears. Estimates based on hunter kill rates of marked bears gave minimum and maximum estimates of about 300 and 900 bears, respectively. Although these are not confidence intervals of the total population estimate, we believe that the true population size is included within these limits. Densities within the female core areas varied from 50 to 100% of those in similar habitats in European Russia. The bear population in Sweden appeared to have increased at a stable rate of about 1·5% annually during the past 50 years. Mean annual rate of legal harvest during 1943–1991 was estimated to be 5·5% (±2·1% SD), suggesting a maximum sustainable rate of 7·0% for this population. The harvest increased at a rate of 9·6% annually during 1981–1991, and apparently was at the maximum sustainable level during 1987–1991.