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1. Invasive alien species are among the most important threats to biodiversity. Plans for their eradication have been implemented worldwide but estimating residual population size and eradication probability to assess removal success is complicated by the imperfect detection of residual individuals. 2. Most methods to assess residual abundance and eradication probability rely on the often unrealistic assumption that a population is closed to mortality and recruitment processes during the implementation of removal actions. We extended existing removal models and developed a novel analytical approach to estimate residual population size and derive eradication probability in open populations, while accounting for multiple removal methods. 3. We apply this approach to 20 eradication projects in Europe and the United States that used mechanical methods to return high mountain lakes to their original fishless condition. 4. The new removal model incorporates i) a mechanistic description of the ecological process underlying survival and recruitment probabilities during the eradication period, and ii) the use of multiple, concomitant removal methods (i.e., electrofishing, gillnetting, fyke-netting) at multiple sites simultaneously. 5. We used a subset of “control” lakes where eradication success was confirmed by more than 5 years of post-removal surveys to validate the model. For these lakes, eradication success, evaluated by whether the 95% Bayesian credible interval for estimated residual population size encompassed values of less than 2 individuals, was confirmed in 13 out of 15 lake-by-species case studies. In addition, the model correctly assigned an eradication probabilities equal to 0 for the eradications that are still in progress. 6. Synthesis and applications. Our study provides insights into the dynamics of fish populations subject to eradication in high mountain lakes of different countries. In addition, the analytical approach proposed accounts for demographic processes and multiple removal methods in multiple sites and seasons. It can represent an informative tool to estimate residual population size and eradication probability of alien species to optimize eradication efforts and efficacy of conservation actions. The extension to open populations makes the approach useful to evaluate long-term eradication plans.

The snow leopard Panthera uncia is an elusive and globally-threatened apex predator occurring in the mountain ranges of central Asia. As with other large carnivores, gaps in data on its distribution and abundance still persist. Moreover, available density estimates are often based on inadequate sampling designs or analytical approaches. Here, we used camera trapping across a vast mountainous area (area of the sampling frame 850 km2 ; analysed habitat extent 2600 km2 ) and spatially-explicit capture-recapture (SECR) models to provide, to our knowledge, the frst robust snow leopard population density estimate for the Altai Mountains. This region is considered one of the most important conservation areas for snow leopards, representing a vast portion of suitable habitat and a key ecological corridor. We also provide estimates of the scale parameter (σ) that refects ranging behaviour (activity range) and baseline encounter probability, and investigated potential drivers of density and related parameters by assessing their associations with anthropogenic and environmental factors. Sampling yielded 9729 images of snow leopards corresponding to 224 independent detections that belonged to a minimum of 23 identifed adult individuals. SECR analysis resulted in an overall density of 1.31 individuals/100 km2 (1.15%–1.50 95% CI), which was positively correlated with terrain slope. This estimate falls within the midvalues of the range of density estimates for the species globally. We estimated signifcantly diferent activity range size for females and males (79 and 329 km2 , respectively). Baseline encounter probability was negatively associated with anthropogenic activity. Our study contributes to on-going eforts to produce robust global estimates of population abundance for this top carnivore. Bibliografija: str. 272-275.

Numerous protected areas (PAs) have been created worldwide to safeguard wildlife and other natural resources from anthropogenic threats such as habitat destruction and bushmeat hunting. However, conservation efforts in many tropical PAs are still inadequate, revealing deficiencies in management effectiveness. It is therefore important to quantify how different protection regimes impact wildlife within PAs. We investigated the differences between forest mammal communities in two ecologically comparable PAs in the Udzungwa Mountains (Tanzania) with contrasting management regimes. One is a well-protected national park with efficient law enforcement; the other has suffered decades of inadequate protection, mainly resulting in high levels of illegal hunting. Using camera-trapping data, we assessed the target communities in terms of species richness, functional composition (i.e. proportions of trophic guilds) and species-specific occurrences, all while accounting for imperfect detection. We found striking differences between the two mammal communities: lower species richness, alteration in the trophic structure and reduced occurrence probabilities for most species in the forest with high disturbance. The difference in occurrence probability between the two PAs tended to be highest for larger-bodied species. Our results show that strictly enforced legal protection is required to maintain diverse mammal communities in tropical forests under ever-increasing anthropogenic threats. While PAs are the cornerstone of efforts to conserve tropical biodiversity, the future of biodiversity within them is closely tied to the effectiveness of enforcement.

This work was supported by the Peace Parks Foundation; G.C.S. was funded by a doctoral grant from Fundacão para a Ciência e a Tecnologia (FCT: PD/BD/114037/2015); L.H.S. was supported by the National Research Foundation, South Africa (UID: 107099 and 115040) and by the African Institute for Conservation Ecology. Apex predator reintroductions have proliferated across southern Africa, yet their ecological effects and proposed umbrella benefits of associated management lack empirical evaluations. Despite a rich theory on top-down ecosystem regulation via mesopredator suppression, a knowledge gap exists relating to the influence of lions (Panthera leo) over Africa's diverse mesocarnivore (less than 20 kg) communities. We investigate how geographical variation in mesocarnivore community richness and occupancy across South African reserves is associated with the presence of lions. An interesting duality emerged: lion reserves held more mesocarnivore-rich communities, yet mesocarnivore occupancy rates and evenness-weighted diversity were lower in the presence of lions. Human population density in the reserve surroundings had a similarly ubiquitous negative effect on mesocarnivore occupancy. The positive association between species richness and lion presence corroborated the umbrella species concept but translated into small differences in community size. Distributional contractions of mesocarnivore species within lion reserves, and potentially corresponding numerical reductions, suggest within-community mesopredator suppression by lions, probably as a result of lethal encounters and responses to a landscape of fear. Our findings offer empirical support for the theoretical understanding of processes underpinning carnivore community assembly and are of conservation relevance under current large-predator orientated management and conservation paradigms. Postprint

Amphibian conservation has progressed from the identification of declines to mitigation, but efforts are hampered by the lack of nuanced information about the effects of environmental characteristics and stressors on mechanistic processes of population regulation. Challenges include a paucity of long-term data and scant information about the relative roles of extrinsic (e.g., weather) and intrinsic (e.g., density dependence) factors. We used a Bayesian formulation of an open population capture-recapture model and &gt, 30 years of data to examine intrinsic and extrinsic factors regulating two adult boreal chorus frogs (Pseudacris maculata) populations. We modelled population growth rate and apparent survival directly, assessed their temporal variability, and derived estimates of recruitment. Populations were relatively stable (geometric mean population growth rate &gt, 1) and regulated by negative density dependence (i.e., higher population sizes reduced population growth rate). In the smaller population, density dependence also acted on adult survival. In the larger population, higher population growth was associated with warmer autumns. Survival estimates ranged from 0.30&ndash, 0.87, per-capita recruitment was &lt, 1 in most years, and mean seniority probability was &gt, 0.50, suggesting adult survival is more important to population growth than recruitment. Our analysis indicates density dependence is a primary driver of population dynamics for P. maculata adults.

Recent technological and methodological advances have revolutionized wildlife monitoring. Although most biodiversity monitoring initiatives are geared towards focal species of conservation concern, researchers are increasingly studying entire communities, specifically the spatiotemporal drivers of community size and structure and interactions among species. This has resulted in the emergence of multi-species occupancy models (MSOMs) as a promising and efficient approach for the study of community ecology. Given the potential of MSOMs for conservation and management action, it is critical to know whether study design and model assumptions are consistent with inference objectives. This is especially true for studies that are designed for a focal species but can give insights about a community. Here, we review the recent literature on MSOMs, identify areas of improvement in the multi-species study workflow, and provide a reference model for best practices for focal species and community monitoring study design. We reviewed 92 studies published between 2009 and early 2018, spanning 27 countries and a variety of taxa. There is a consistent under-reporting of details that are central to determining the adequacy of designs for generating data that can be used to make inferences about community-level patterns of occupancy, including the spatial and temporal extent, types of detectors used, covariates considered, and choice of field methods and statistical tools. This reporting bias could consequently result in skewed estimates, affecting conservation actions and management plans. On the other hand, comprehensive reporting is likely to help researchers working on MSOMs assess the robustness of inferences, in addition to making strides in terms of reproducibility and reusability of data. We use our literature review to inform a roadmap with best practices for MSOM studies, from simulations to design considerations and reporting, for the collection of new data as well as those involving existing datasets.

Este artículo contiene 10 páginas, 4 figuras, 1 tabla., 1. The Strait of Gibraltar is an important habitat for cetaceans due to its high marine productivity. However, it is also the second most navigated channel in the world, subjecting cetaceans to a high level of vessel traffic, including an established whale-watching fleet. Both maritime traffic and whale-watching activities have been shown to impact the behaviour of cetaceans, but little is known about their impact on the demography and dynamics of cetacean populations. 2. The aim of this study was to evaluate the impacts of both ferry traffic and whalewatching vessels on the apparent survival probability of a bottlenose dolphin (Tursiops truncatus) population that occurs in the Strait. 3. A Bayesian hierarchical mark–recapture modelling approach was applied to 8 years of photo-identification data (2002–2009). Apparent annual survival probability was negatively correlated with ferry traffic, which explained >70% of temporal variation in survival, in contrast to whale-watching, the effect of which was almost negligible. Despite these results, other natural and human-related factors are likely to drive apparent survival in the study area. 4. Abundance increased between 2002 and 2005, and then decreased between 2006 and 2009, while local per-capita recruitment decreased from 2004 until the end of the study period. These shifts correlated temporally with the construction of a large harbour on the Moroccan coast, which increased maritime traffic significantly, including a 40% increase in ferry traffic that regularly transited the Strait. 5. These results highlight the need to better understand the impact of maritime traffic on the demography of the dolphin population in the Strait, in order to implement evidence-based conservation regulations in a region of high cetacean occurrence., Funds were partially provided by the Spanish Ministry of Economy and Innovation (ref. CGL2009-08298), Loro Parque Foundation, CEPSA, the Spanish Ministry of the Environment, Fundación Biodiversidad and two EU LIFE programme grants (ref. LIFE07NAT/E/000732 and LIFE02NAT/E/8610). R. de Stephanis was supported by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa SEV2012-0262; Juan de la Cierva programme).

Funding: Data in this publication were provided by the Tropical Ecology Assessment and Monitoring (TEAM) Network, a collaboration between Conservation International, the Smithsonian Inst., and the Wildlife Conservation Society, and partially funded by these institutions, the Gordon and Betty Moore Foundation, and other donors. The understanding of global diversity patterns has benefitted from a focus on functional traits and how they relate to variation in environmental conditions among assemblages. Distant communities in similar environments often share characteristics, and for tropical forest mammals, this functional trait convergence has been demonstrated at coarse scales (110–200 km resolution), but less is known about how these patterns manifest at fine scales, where local processes (e.g. habitat features and anthropogenic activities) and biotic interactions occur. Here, we used standardized camera trapping data and a novel analytical method that accounts for imperfect detection to assess how the functional composition of terrestrial mammal communities for two traits – trophic guild and body mass – varies across 16 protected areas in tropical forests and three continents, in relation to the extent of protected habitat and anthropogenic pressures. We found that despite their taxonomic differences, communities generally have a consistent trophic guild composition, and respond similarly to these factors. Insectivores were found to be sensitive to the size of protected habitat and surrounding human population density. Body mass distribution varied little among communities both in terms of central tendency and spread, and interestingly, community average body mass declined with proximity to human settlements. Results indicate predicted trait convergence among assemblages at the coarse scale reflects consistent functional composition among communities at the local scale, suggesting that broadly similar habitats and selective pressures shaped communities with similar trophic strategies and responses to drivers of change. These similarities provide a foundation for assessing assemblages under anthropogenic threats and sharing conservation measures. Publisher PDF

Protected areas (PAs) in the tropics are vulnerable to human encroachment, and, despite formal protection, they do not fully mitigate anthropogenic threats to habitats and biodiversity. However, attempts to quantify the effectiveness of PAs and to understand the status and changes of wildlife populations in relation to protection efficiency remain limited. Here, we used camera‐trapping data collected over 8 consecutive years (2009–2016) to investigate the yearly occurrences of medium‐to‐large mammals within the Udzungwa Mountains National Park (Tanzania), an area of outstanding importance for biological endemism and conservation. Specifically, we evaluated the effects of habitat and proxies of human disturbance, namely illegal hunting with snares and firewood collection (a practice that was banned in 2011 in the park), on species' occurrence probabilities. Our results showed variability in species' responses to disturbance: The only species that showed a negative effect of the number of snares found on occurrence probability was the Harvey's duiker, a relatively widespread forest antelope. Similarly, we found a moderate positive effect of the firewood collection ban on only the suni, another common antelope, and a negative effect on a large opportunistic rodent, the giant‐pouched rat. Importantly, we found evidence of temporal stability in occurrence probability for all species over the 8‐year study period. Our findings suggest that well‐managed PAs can sustain mammal populations in tropical forests. However, variability among species in their responses to anthropogenic disturbance necessitates consideration in the design of conservation action plans for multiple taxa., Protected areas (PAs) in the tropics are vulnerable to human encroachment, but attempts to quantify their effectiveness remain limited. We used camera‐trapping data collected over 8 consecutive years to evaluate the effects of proxies of human disturbance on the yearly occurrences of forest mammals within the Udzungwa Mountains National Park (Tanzania). Our results showed variability in species' responses to disturbance, and we also found evidence of temporal stability in occurrence probability for all species over the study period, suggesting that well‐managed PAs can sustain mammal populations in tropical forests.

Understanding the impact of livestock on native wildlife is of increasing conservation relevance. For the Vulnerable snow leopard Panthera uncia, wild prey reduction, intensifying human–wildlife conflicts and retaliatory killings are severe threats potentially exacerbated by the presence of livestock. Elucidating patterns of co-occurrence of snow leopards, wild ungulate prey, and livestock, can be used to assess the compatibility of pastoralism with conservation. We used camera trapping to study the interactions of livestock, Siberian ibex Capra sibirica and snow leopards in a national park in the Altai mountains, Mongolia. We obtained 494 detections of wild mammals and 912 of domestic ungulates, dogs and humans. Snow leopards and Siberian ibex were recorded 14 and 33 times, respectively. Co-occurrence modelling showed that livestock had a higher estimated occupancy (0.65) than ibex, whose occupancy was lower in the presence of livestock (0.11) than in its absence (0.34–0.35 depending on scenarios modelled). Snow leopard occupancy did not appear to be affected by the presence of livestock or ibex but the robustness of such inference was limited by uncertainty around the estimates. Although our sampling at presumed snow leopard passing sites may have led to fewer ibex detections, results indicate that livestock may displace wild ungulates, but may not directly affect the occurrence of snow leopards. Snow leopards could still be threatened by livestock, as overstocking can trigger human–carnivore conflicts and hamper the conservation of large carnivores. Further research is needed to assess the generality and strength of our results.

In countries such as Mongolia, where globalization of the cashmere market has spurred herders to massively increase their livestock numbers, an important conservation concern is the effect of livestock encroachment on wildlife. This is especially important inside protected areas (PAs), which often represent the last refugia for threatened large mammals. We used camera-traps to sample four areas with different protection status across the Mongolian Altai Mountains, and targeted a predator-prey system composed of livestock, one large herbivore, the Siberian ibex, and two large carnivores, the snow leopard and the wolf. To determine the effect of livestock on habitat use by the wild species and their spatio-temporal co-occurrence we applied an occupancy framework explicitly developed for modelling interacting species. We recorded a widespread presence of domestic animals in the PAs, and observed avoidance of sites used by livestock by snow leopard and ibex, while wolves tended to co-occur with it. Snow leopard and ibex showed clear mutual co-occurrence, indicating a tight predator-prey relationship. Results provide evidence that, at the scale of sites sampled primarily to maximise snow leopard detections, grazing livestock interferes with wild species by inducing avoidance in snow leopards, and attraction in wolves. We suggest that (1) PAs management should enforce real grazing limitations on the ground, especially in the core areas of the parks; (2) new policies incorporating wildlife conservation into government subsidies to pastoralists should be envisaged, to prevent increasing displacement of snow leopards and ibex; (3) as wolves co-occurred with livestock, with the potential for human-wildlife conflicts, we encourage the use of a set of prevention techniques to mitigate livestock depredation.

Including ecological specialization (e.g. functional guild) in analyses performed across regions can help to study how size and structure of communities vary across environmental gradients. Multi-species occupancy models, and their extension to a multi-region framework, represent useful tools for such gradient analysis based on functional traits. However, in these models species richness is only a derived parameter and therefore explicit relationships cannot be inferred. We provide a novel hierarchical multi-region community model that allows for direct modeling of trait-based patterns of species richness along environmental gradients by partitioning communities into ecologically relevant strata (e.g. guilds). We illustrate the flexibility of the model by simulations, where we estimate guild richness and community composition using both categorical and continuous species traits. In addition, we apply our model to data from eight avian communities to explore how guild richness varies across elevational gradients. Simulations indicate that the model is able to estimate relationships between guild richness and environmental gradients even when the number of regions is low. Applying the model to the bird community data set, we show how the number of species in four feeding guilds varies in different ways across an elevational gradient. Understanding large scale variation in species richness and how it relates to environmental gradients requires an explicit treatment of community structure. Our modeling approach allows to test hypotheses directly and simultaneously on strata- and community-specific species richness while accounting for the issues of rarity and detectability, and can be used to investigate the mechanisms which shape large scale spatial variation in species richness. This article is protected by copyright. All rights reserved.

Accurate estimations of the abundance of threatened animal populations are required for assessment of species' status and vulnerability and conservation planning. However, density estimation is usually difficult and resource demanding, so researchers often collect data at local scales. However, anthropogenic pressures most often have landscape-level effects, for example, through habitat loss and fragmentation. We applied hierarchical distance sampling (HDS) to transect count data to determine the effect of habitat and anthropogenic factors on the density of 3 arboreal primate species inhabiting 5 distinct tropical forests across a landscape of 19,000 kmEfectos de la Perturbación Antropogénica sobre la Densidad de Primates a Escala de Paisaje Resumen Se requieren estimaciones correctas del tamaño de las poblaciones de animales amenazados para evaluar el estado y la vulnerabilidad de las especies y así planear su conservación. Sin embargo, la estimación de la densidad es usualmente complicada y demanda recursos, así que los investigadores con frecuencia recolectan la información a escala local, a pesar de que la presión antropogénica suele tener efectos a nivel del paisaje; por ejemplo, la pérdida del hábitat y la fragmentación. Aplicamos un muestro jerárquico a distancia (HDS, en inglés) para contar datos por transecto y determinar el efecto de los factores del hábitat y los factores antropogénicos sobre la densidad de tres especies de primates arbóreos en un paisaje de 19,000 km物种濒危等级、易危性的评估及保护规划需要对濒危动物种群数量进行准确估计。但是密度估计通常较为困难, 且对资源的需求较高, 因此研究者一般只能收集局部尺度的数据。然而, 人为压力的影响常常是景观尺度的, 例如导致生境丧失和破碎化。我们在坦桑尼亚乌德宗瓦山脉 (Udzungwa Mountains) 19,000 平方千米的景观尺度中, 采用分层距离取样法收集样带计数数据, 确定了生境和人为因素对三种栖息在五个不同的热带森林树栖灵长类物种种群密度的影响。我们发展了一种新的多区域分层距离取样法, 可以在不丢失位置特异信息的情况下对跨越多个森林的物种种群密度和可探测性统一建模。对所有这三个物种来说, 人为干扰对集合种群密度的影响整体上都是负面的: 安哥拉疣猴 (Colobus angolensis palliatus) 为 −0.63 (95 % 贝叶斯置信区间为 −1.03 到 −0.27); 乌德宗瓦红疣猴 (Procolobus gordonorum) 为 −0.54 (95 % 贝叶斯置信区间为 −0.89 到 −0.22); 青猴 (Cercopithecus mitis monoides) 为 −0.33 (95 % 贝叶斯置信区间为 −0.63 到 −0.07) 。它们对生境因素的响应有共同之处, 特别是海拔的负面影响和攀缘植物覆盖度的积极作用。这些结果对保护科学和实践十分重要, 因为种群间对人为干扰共同的负面响应为发展景观尺度上的保护计划提供了基础, 这样的保护实践更为全面且成本效益高; 物种间的响应一致性则表明保护措施可能可以推广到多物种水平, 考虑到灵长类动物对热带雨林的重要功能, 这一点意义重大; 而灵长类在海拔低、与人类居住地较近的地区密度更高, 这指明了具体的管理建议, 例如确立缓冲区和优先保护区域。【翻译: 胡怡思; 审校: 聂永刚】.

We analysed the long-term (1975-2017) population response of a colony of a marine top predator, the black-legged kittiwake Rissa tridactyla, to the population dynamics of sardine Sardina pilchardus, its main local prey. The study site (Sisargas Islands, Spain) is located at the southernmost edge of the geographical distribution of the predator. Kittiwake counts of breeding pairs started with the discovery of the colony (1975), likely close to the actual year of first colonization. Sardine landings by age class (1978-2016) were taken from the International Council for the Exploration of the Sea (ICES) database. Sequential t-test analysis revealed that a regime shift of the oldest sardine age class (age 6+) took place in 1991 and that kittiwakes experienced a regime shift in the number of breeding pairs in 1993, 2 yr after the prey shift. Multiple autocorrelation functions for the detrended time series of sardines and kittiwakes indicated an autocorrelation with a time lag of 2 yr. Despite much reduced fishing effort, sardine densities have not recovered since the collapse, likely due to changes in large-scale atmospheric circulation in the Northern Hemisphere in the late 1990s. Kittiwakes at Sisargas have not recovered demographically, remaining nearly extinct during the last ca. 20 yr. Although we lack detailed demographic data for the studied kittiwake population, we suggest that massive breeding failure and subsequent dispersal to higher-quality patches might explain the rapid non-linear collapse in breeding population density. We discuss some behavioural social responses that may have occurred during and after the collapse to explain the dynamics of the study colony.

The conservation of wildlife requires management based on quantitative evidence, and especially for large carnivores, unraveling cause-specific mortalities and understanding their impact on population dynamics is crucial. Acquiring this knowledge is challenging because it is difficult to obtain robust long-term data sets on endangered populations and, usually, data are collected through diverse sampling strategies. Integrated population models (IPMs) offer a way to integrate data generated through different processes. However, IPMs are female-based models that cannot account for mate availability, and this feature limits their applicability to monogamous species only. We extended classical IPMs to a two-sex framework that allows investigation of population dynamics and quantification of cause-specific mortality rates in nonmonogamous species. We illustrated our approach by simultaneously modeling different types of data from a reintroduced, unhunted brown bear (Ursus arctos) population living in an area with a dense human population. In a population mainly driven by adult survival, we estimated that on average 11% of cubs and 61% of adults died from human-related causes. Although the population is currently not at risk, adult survival and thus population dynamics are driven by anthropogenic mortality. Given the recent increase of human-bear conflicts in the area, removal of individuals for management purposes and through poaching may increase, reversing the positive population growth rate. Our approach can be generalized to other species affected by cause-specific mortality and will be useful to inform conservation decisions for other nonmonogamous species, such as most large carnivores, for which data are scarce and diverse and thus data integration is highly desirable.

Summary An enduring challenge in ecology is to understand what drives spatial variation in the size and structure of communities. The ability to count the number of species present at a location is hindered by the fact that not all species are equally detectable, and invariably some go completely undetected. This makes comparing species richness across distinct spatial units (or regions) problematic as sources of error are usually unaccounted for in simple enumerations of species. Multi-species occupancy models explicitly incorporate a model for this observation uncertainty and provide a framework for estimating community size when detection is imperfect. Currently, however, the model is restricted to estimating the number of species at only a single region of interest. In this paper we extend the multi-species occupancy model to accommodate data collected across multiple regions of interest (e.g., reserves or biomes). We report improved model performance of the joint multiregion approach when compared to the more traditional two-stage approach of modelling spatial variation in species richness using simulations. Then, applying the model to data collected from eight avian communities in northern Italy, we demonstrate how species richness can be modeled as a spatially varying function of habitat complexity. Extending the multi-species occupancy model to accommodate data collected across multiple regions of interest (e.g., reserves or biomes) allows for joint estimation of region-specific community size and permits species richness to be modeled as a function of region-specific covariates. Our approach provides a mechanism for testing hypotheses about why and how species richness varies across space.

Determining correlates of density for large carnivores is important to understand their ecological requirements and develop conservation strategies. Of the several earlier density studies conducted, few were done at a scale that allows inference about the correlates of density over heterogeneous landscapes. We deployed 164 camera trap stations covering ~2500 km2 across five distinct habitats in the Udzungwa Mountains, Tanzania, to investigate correlates of density for a widespread and adaptable carnivore, the leopard (Panthera pardus). We modelled data in a capture-recapture framework, with both biotic and abiotic covariates hypothesised to influence leopard density. We found that leopard density increased with distance to protected area borders (mean±SE estimated effect = 0.44±0.20), a proxy for both protected area extent and distance from surrounding human settlements. Second, we detected a weak positive relationship between leopard density and estimated mean prey occupancy, while density was not related to habitat type. We estimated mean leopard density at 3.84 individuals/100km2 (95% CI = 2.53 ? 5.85/100km2), with relatively moderate variation across habitat types. These results indicate that protected habitat extent and anthropogenic disturbance seemingly limit leopard populations more than prey abundance or habitat type. Such vulnerability is relevant to the conservation of this carnivore, which is generally considered more resilient to human disturbance than other large cats. Our findings support the notion that protected areas are important to preserve viable population of leopards, increasingly so in times of unprecedented habitat fragmentation. Protection of buffer zones smoothing the abrupt impact of human activities at reserve edges also appears of critical conservation relevance.

Este artículo contiene 8 páginas, 2 figuras., The relative role of density-dependent and density-independent variation in vital rates and population size remains largely unsolved. Despite its importance to the theory and application of population ecology, and to conservation biology, quantifying the role and strength of density dependence is particularly challenging. We present a hierarchical formulation of the temporal symmetry approach, also known as the Pradel model, that permits estimation of the strength of density dependence from capture–mark–reencounter data. A measure of relative population size is built in the model and serves to detect density dependence directly on population growth rate. The model is also extended to account for temporal random variability in demographic rates, allowing estimation of the temporal variance of population growth rate unexplained by density dependence. We thus present a model-based approach that enable to test and quantify the effect of density-dependent and density-independent factors affecting population fluctuations in a single modeling framework. More generally, we use this modeling framework along with simulated and empirical data to show the value of including density dependence when modeling individual encounter data without the need for auxiliary data, Funds were partially provided by the Spanish Ministry of Economy (ref. CGL2013-42203-R and ref. CGL2017-85210-P). G. Tavecchia, R. Pradel and D. Oro were partly supported by a joint grant (PICS INTERACT, reference 272847) from CNRS in France and CSIC in Spain.

Recently-developed methods that integrate multiple data sources arising from the same ecological processes have typically utilized structured data from well-defined sampling protocols (e.g., capture-recapture and telemetry). Despite this new methodological focus, the value of opportunistic data for improving inference about spatial ecological processes is unclear and, perhaps more importantly, no procedures are available to formally test whether parameter estimates are consistent across data sources and whether they are suitable for integration. Using data collected on the reintroduced brown bear population in the Italian Alps, a population of conservation importance, we combined data from three sources: traditional spatial capture-recapture data, telemetry data, and opportunistic data. We developed a fully integrated spatial capture-recapture (SCR) model that included a model-based test for data consistency to first compare model estimates using different combinations of data, and then, by acknowledging data-type differences, evaluate parameter consistency. We demonstrate that opportunistic data lend itself naturally to integration within the SCR framework and highlight the value of opportunistic data for improving inference about space use and population size. This is particularly relevant in studies of rare or elusive species, where the number of spatial encounters is usually small and where additional observations are of high value. In addition, our results highlight the importance of testing and accounting for inconsistencies in spatial information from structured and unstructured data so as to avoid the risk of spurious or averaged estimates of space use and consequently, of population size. Our work supports the use of a single modeling framework to combine spatially-referenced data while also accounting for parameter consistency.

ummary Local recruitment and immigration play an important part in the dynamics and growth of animal populations. However, their estimation and incorporation into open populations models is, in most cases, problematic. We studied factors affecting the growth of a recently established colony of Eurasian spoonbill (Platalea leucorodia) and assessed the contribution of local recruits, i.e. birds born in the colony, and immigrants, i.e. birds of unknown origin, to colony growth. We applied an integrated population model that accounts for uncertainty in breeding state assignment and merges population surveys, local fecundity and individual longitudinal data of breeding and non-breeding birds, to estimate demographic rates and the relative role of recruitment and immigration in driving the local dynamics. We also used this analytical framework to assess the degree of support for the ʻperformance-basedʼ and ʻconspecific attractionʼ hypotheses as possible mechanisms of colony growth. Among the demographic rates, only immigration was positively and significantly correlated with population growth rate. In addition, the number of immigrants settling in the colony was positively correlated with colony size in the previous and current year, but was not correlated with fecundity of the previous year. Our results suggest that the variation in immigration affected colony dynamics and that conspecific attraction likely triggered the relevant role of immigration in the growth of a recently formed waterbird colony, supporting the need of including immigration in population analysis. This article is protected by copyright. All rights reserved.

Information on the effectiveness of wildlife management actions is scarce, despite the great relevance of this type of information for maximizing conservation goals while minimizing resource expenditure. Here we assess the management effectiveness of a four-year hunting moratorium, addressed to protecting a declining waterbird game species: common coot Fulica atra. We also studied the indirect benefits that this management action could have had on a non-target endangered species (crested coot Fulica cristata), currently being reintroduced in the study region (Comunidad Valenciana, eastern Spain). We found that wintering common coots interrupted their marked negative trend coinciding with the hunting moratorium, and Before-After-Control-Impact modelling confirmed this fact. However breeding common coots continued their negative trend in numbers. We also found that crested coots increased their wintering numbers during the hunting moratorium years but not during breeding. We detected a strong and time variant cost of release on survival probability of crested coots, but annual survival probability was found to be constant and low for experienced birds, with no clear effects of the hunting moratorium on survival probability. We conclude that the moratorium had some positive effect on both species, but we suggest that lack of enforcement during a traditional hunting practice at the end of each hunting season, most likely precluded the moratorium having a long-lasting effect on the breeding numbers and probably on survival, of both species. Hence, when fully-enforced hunting moratoria are difficult to implement, we recommend the creation of hunting preserves of high habitat quality to attract coots during the winter, allowing its subsequent reproduction during the breeding season. © 2013 Elsevier Ltd., This study has been funded by the Spanish Ministry of Science (Grant Ref. CGL2009-08298), the Regional Government of Balearic Islands (FEDER funding) and by the regional government of Comunidad Valenciana (Generalitat Valenciana). AMA was funded by an Isidro Parga Pondal postdoctoral contract from Xunta de Galicia

Current climatic changes have increased the need to forecast population responses to climate variability. A common approach to address this question is through models that project current population state using the functional relationship between demographic rates and climatic variables. We argue that this approach can lead to erroneous conclusions when interpopulation dispersal is not considered. We found that immigration can release the population from climate-driven trajectories even when local vital rates are climate dependent. We illustrated this using individual-based data on a trans-equatorial migratory seabird, the Scopoli's shearwater Calonectris diomedea, in which the variation of vital rates has been associated with large-scale climatic indices. We compared the population annual growth rate λ, estimated using local climate-driven parameters with ρ, a population growth rate directly estimated from individual information and that accounts for immigration. While λ varied as a function of climatic variables, reflecting the climate-dependent parameters, ρ did not, indicating that dispersal decouples the relationship between population growth and climate variables from that between climatic variables and vital rates. Our results suggest caution when assessing demographic effects of climatic variability especially in open populations for very mobile organisms such as fish, marine mammals, bats, or birds. When a population model cannot be validated or it is not detailed enough, ignoring immigration might lead to misleading climate-driven projections., This research was partially funded by the Spanish Minister of Economy and Innovation (project number: CGL2013-42203-R).

Growing threats to primates in tropical forests make robust and long-term population abundance assessments increasingly important for conservation. Concomitantly, monitoring becomes particularly relevant in countries with primate habitat. Yet monitoring schemes in these countries often suffer from logistic constraints and/or poor rigor in data collection, and a lack of consideration of sources of bias in analysis. To address the need for feasible monitoring schemes and flexible analytical tools for robust trend estimates, we analyzed data collected by local technicians on abundance of three species of arboreal monkey in the Udzungwa Mountains of Tanzania (two Colobus species and one Cercopithecus), an area of international importance for primate endemism and conservation. We counted primate social groups along eight line transects in two forest blocks in the area, one protected and one unprotected, over a span of 11 years. We applied a recently proposed open metapopulation model to estimate abundance trends while controlling for confounding effects of observer, site, and season. Primate populations were stable in the protected forest, while the colobines, including the endemic Udzungwa red colobus, declined severely in the unprotected forest. Targeted hunting pressure at this second site is the most plausible explanation for the trend observed. The unexplained variability in detection probability among transects was greater than the variability due to observers, indicating consistency in data collection among observers. There were no significant differences in both primate abundance and detectability between wet and dry seasons, supporting the choice of sampling during the dry season only based on minimizing practical constraints. Results show that simple monitoring routines implemented by trained local technicians can effectively detect changes in primate populations in tropical countries. The hierarchical Bayesian model formulation adopted provides a flexible tool to determine temporal trends with full account for any imbalance in the data set and for imperfect detection.

© 2015 British Ecological Society. With ongoing climate change, many species are expected to shift their spatial and temporal distributions. To document changes in species distribution and phenology, detection/non-detection data have proven very useful. Occupancy models provide a robust way to analyse such data, but inference is usually focused on species spatial distribution, not phenology. We present a multi-season extension of the staggered-entry occupancy model of Kendall et al. (2013, Ecology, 94, 610), which permits inference about the within-season patterns of species arrival and departure at sampling sites. The new model presented here allows investigation of species phenology and spatial distribution across years, as well as site extinction/colonization dynamics. We illustrate the model with two data sets on European migratory passerines and one data set on North American treefrogs. We show how to derive several additional phenological parameters, such as annual mean arrival and departure dates, from estimated arrival and departure probabilities. Given the extent of detection/non-detection data that are available, we believe that this modelling approach will prove very useful to further understand and predict species responses to climate change., U.S. Geological Survey-Amphibian Research and Monitoring Initiative (ARMI). Grant Number: 505; Autonomous Province of Trento

The decline of important coastal habitats, like seagrass meadows, is likely to influence populations of associated species, like the noble pen shell, Pinna nobilis. Here we used a Bayesian formulation of individual covariate models to derive a reliable estimate of populations of P. nobilis in shallow, and thus usually most impacted, areas around the island of Majorca, Balearic Islands, Spain. At six evaluated sites we find quite distinct densities ranging from 1.4 to 10.0 individuals/100m2. These differences in density could not be explained by habitat factors like shoot density and meadow cover, nor did dislodgement by storms (evaluated by maximum wind speeds at the sites) seem to play an important role. However, noble pen shell density was related to anchoring as at sites where anchoring was not permitted the average density was 7.9 individuals/100m2 while in sites where ships anchored the density was on average 1.7 individuals/100m2. As for the conservation of Posidonia oceanica meadows, for the associated population of P. nobilis it would be of utmost importance to reduce anchoring pressure as a conservation measure for these endangered and protected bivalves. © 2013 Elsevier Ltd.

Evidence for decline or threat of wild populations typically comes from multiple sources and methods that allow optimal integration of the available information, representing a major advance in planning management actions. We used integrated population modelling and perturbation analyses to assess the demographic consequences of the illegal use of poison for an insular population of Red Kites, Milvus milvus. We first pooled into a single statistical framework the annual census of breeding pairs, the available individual-based data, the average productivity and the number of birds admitted annually to the local rehabilitation centre. By combining these four types of information we were able to increase estimate precision and to obtain an estimate of the proportion of breeding adults, an important parameter that was not directly measured in the field and that is often difficult to assess. Subsequently, we used perturbation analyses to measure the expected change in the population growth rate due to a change in poison-related mortality. We found that poison accounted for 0.43 to 0.76 of the total mortality, for yearlings and older birds, respectively. Results from the deterministic population model indicated that this mortality suppressed the population growth rate by 20%. Despite this, the population was estimated to increase, albeit slowly. This positive trend was likely maintained by a very high productivity (1.83 fledglings per breeding pair) possibly promoted by supplementary feeding, a situation which is likely to be common to many large obligate or facultative European scavengers. Under this hypothetical scenario of double societal costs (poisoning of a threatened species and feeding programs), increasing poison control would help to lower the public cost of maintaining supplementary feeding stations. © 2012 Tenan et al.

Disentangling the influence of demographic parameters and the role of density dependence on species’ population dynamics may be challenging, especially when there are fractions of the population that are unobservable (e.g. dispersers, non-breeders). Additionally, due to the difficulty of gathering data at large spatial scales, most studies ignore the global dynamic of a species, which would integrate heterogeneity in local dynamics and remove the noise of dispersal. We developed a global scale, integrated population model (IPM), to disentangle the main demographic drivers of population dynamics in a long-lived colonial seabird. We used 28 years of Audouin’s gull demographic data encompassing 69 local patches (90% of the world population). Importantly, we took into account the unobservable fraction of non-breeders and also assessed the strength of density dependence for this fraction of the population. As predicted by life histories of long-lived organisms, temporal random variation in survival was highest for immatures (), and lowest for adults (). Large temporal fluctuations in the probability of taking a sabbatical from reproduction would partly explain constancy in adult survival, adults probably refraining from breeding when environmental conditions were harsh. Thus, skipping breeding would be a bet hedging strategy for long-lived organisms having many reproductive chances during their lifespan. Immature survival and fertility were the main drivers of population dynamics during the study period (r2= 0.83 (0.77-0.87) and 0.73 (0.63-0.79) respectively). We found strong evidence of density dependence, not only due to the number of breeders (r2= -0.34 (-0.43 -0.24)) but also to that of sabbaticals (r2= -0.18 (-0.33 -0.01)). Even though population dynamics of long-lived organisms are very sensitive to changes in adult survival, we show here that in the absence of strong environmental perturbations affecting this life history trait, fluctuations in population density in those species may be driven by variations of immature survival and fertility. The species is showing a 5% of annual global decrease during the last ten years, and we propose an updated species conservation status. Integrated models based on long term monitoring at a global scale may enhance our ecological and evolutionary understanding of how demographic drivers influence population dynamics., M. Genovart is supported by a postdoctoral contract co‐funded by the Regional Government of the Balearic Islands and the European Social Fund. Funds were partially provided by the Spanish Ministry of Economy (ref. CGL2013‐42203‐R and CGL2017‐85210‐P) and the European Union (H2020 RIA‐ MINOUW Grant, ref. H2020‐ 634495).