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Aim Unsustainable hunting is leading to widespread defaunation across the tropics. To mitigate against this threat with limited conservation resources, stakeholders must make decisions on where to focus anti‐poaching activities. Identifying priority areas in a robust way allows decision‐makers to target areas of conservation importance, therefore maximizing the impact of conservation interventions. Location Annamite mountains, Vietnam and Laos. Methods We conducted systematic landscape‐scale surveys across five study sites (four protected areas, one unprotected area) using camera‐trapping and leech‐derived environmental DNA. We analysed detections within a Bayesian multispecies occupancy framework to evaluate species responses to environmental and anthropogenic influences. Species responses were then used to predict occurrence to unsampled regions. We used predicted species richness maps and occurrence of endemic species to identify areas of conservation importance for targeted conservation interventions. Results Analyses showed that habitat‐based covariates were uninformative. Our final model therefore incorporated three anthropogenic covariates as well as elevation, which reflects both ecological and anthropogenic factors. Conservation‐priority species tended to found in areas that are more remote now or have been less accessible in the past, and at higher elevations. Predicted species richness was low and broadly similar across the sites, but slightly higher in the more remote site. Occupancy of the three endemic species showed a similar trend. Main conclusion Identifying spatial patterns of biodiversity in heavily defaunated landscapes may require novel methodological and analytical approaches. Our results indicate that to build robust prediction maps it is beneficial to sample over large spatial scales, use multiple detection methods to increase detections for rare species, include anthropogenic covariates that capture different aspects of hunting pressure and analyse data within a Bayesian multispecies framework. Our models further suggest that more remote areas should be prioritized for anti‐poaching efforts to prevent the loss of rare and endemic species.

Ocelots (Leopardus pardalis) are listed as least concern on the International Union for Conservation of Nature (IUCN) Red list of Threatened Species, yet we lack knowledge on basic demographic parameters across much of the ocelot’s geographic range, including population density. We used camera-trapping methodology and spatially explicit capture-recapture (SECR) models with sex-specific detection function parameters to estimate ocelot densities across 7 field sites over 1 to 12 years (from data collected during 2002–2015) in Belize, Central America. Ocelot densities in the broadleaf rainforest sites ranged between 7.2 and 22.7 ocelots/100 km², whereas density in the pine (Pinus spp.) forest site was 0.9 ocelots/100 km². Applying an inverse-variance weighted average over all years for each broadleaf site increased precision and resulted in average density ranging from 8.5 to 13.0 ocelots/100 km². Males often had larger movement parameter estimates and higher detection probabilities at their activity centers than females. In most years, the sex ratio was not significantly different from 50:50, but the pooled sex ratio estimated using an inverse weighted average over all years indicated a female bias in 1 site, and a male bias in another. We did not detect any population trends as density estimates remained relatively constant over time; however, the power to detect such trends was generally low. Our SECR density estimates were lower but more precise than previous estimates and indicated population stability for ocelots in Belize.

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.

Camera traps are a widely used tool in wildlife research and conservation, but in situ factors such as theft, poor performance in extreme environments and damage by wildlife may be hindering the effectiveness of the technology. However, we still know little about how widespread these constraints are and which are the priorities to solve in the short‐ and mid‐term. We present results from a global survey of camera‐trappers working across a diversity of institutions and habitats, and using camera traps for a range of purposes. We show that: (1) the major current constraints on effective camera‐trapping are cost, theft and sensor performance (with 66%, 50% and 42% of respondents respectively classifying those as important or extremely important barriers for camera‐trapping); (2) the most‐needed technological developments are related to sensor performance (faster triggering responses and higher sensitivity), resistance to extreme environmental conditions (extreme temperatures and high humidity) and automated filtering of blank images; and (3) there is considerable variation among camera trap manufacturers in user‐rated performance, and none of the manufacturer ratings exhibited a trend over time, despite improvements in the technology. Our results serve as valuable market research for both open‐source and commercial camera trap developers. On the basis of our survey of camera‐trappers, we foresee a transition towards camera‐trapping 3.0 in the near‐future, consisting of both more effective camera trap units, but also greater use of wireless data transmission, sensor networks, automation of processes using algorithms and better, more collaborative tools for managing and analysing camera trap data. Ultimately, this will increase the capacity of researchers and conservationists to implement coordinated wildlife monitoring at unprecedented scales. We present results from a global survey of camera‐trappers which show that: (1) the major current constraints on effective camera‐trapping are cost, theft and sensor performance (with 66%, 50% and 42% of respondents respectively classifying those as important or extremely important barriers for camera‐trapping); (2) the most‐needed technological developments are related to sensor performance (faster triggering responses and higher sensitivity), resistance to extreme environmental conditions (extreme temperatures and high humidity) and automated filtering of blank images; and that (3) there is considerable variation among camera trap manufacturers in user‐rated performance, and none of the manufacturer ratings exhibited a trend over time, despite improvements in the technology. Our results serve as valuable market research for both open‐source and commercial camera trap developers.

Flagship species have been used widely as umbrella species (i.e., species with large home range whose protection often provides protection for sympatric species) in the management of China’s nature reserves. This conflation of flagship and umbrella species is best represented by the giant panda (Ailuropoda melanoleuca) and other large, endangered mammals designated as conservation targets in site selection and planning of reserves. Few empirical studies have tested the effectiveness of flagship species as surrogates for a broader range of sympatric species. Using extensive camera-trap data, we examined the effectiveness of management zones designated to protect flagship (target) species in conserving sympatric species in 4 wildlife reserves (Gutianshan, Changqing, Laohegou, and Wolong). We tested whether the progression from peripheral to core zones was associated with an increasing habitat association for both target and sympatric species. The distribution patterns of the study species across the zones in each reserve indicated a disparity between management zones and the species’ habitat requirements. Management zone was included in the final model for all target species, and most of them had higher occurrence in core zones relative to less-protected zones, but zone was not a predictor for most of the sympatric species. When management zone was associated with the occurrence of sympatric species, threatened species generally had higher detections in core zones, whereas common species had higher detections outside of the core zone. Our results suggested that reserve planning based on flagship species does not adequately protect sympatric species due to their specialized habitat requirements. We recommend re-examining the effectiveness of management zoning and urge a multispecies and reserve-wide monitoring plan to improve protection of China’s wildlife. Las especies bandera se han utilizado ampliamente como especies paraguas (es decir, especies con una extensa distribución cuya protección frecuentemente proporciona protección para especies simpátricas) en el manejo de las reservas naturales de China. Esta combinación de especie bandera y especie paraguas tiene su mejor representación en el panda gigante (Ailuropoda melanoleuca) y otros grandes mamíferos en peligro de extinción designados como objetivos de conservación en la selección de sitio y la planeación de reservas. Pocos estudios empíricos han probado la efectividad de las especies bandera como sustitutas de una especie simpátrica con una distribución más amplia. Con datos numerosos de cámaras trampa, examinamos la efectividad de las zonas de manejo designadas para proteger a las especies bandera (objetivo) en la conservación de especies simpátricas dentro de cuatro reservas de fauna (Gutianshan, Changqing, Laohegou y Wolong). Probamos si la progresión de las zonas periféricas hacia las zonas núcleo estaba relacionada con asociaciones crecientes de hábitat tanto para las especies objetivo como para las simpátricas. Los patrones de distribución del estudio de especies a lo largo de las zonas en cada reserva indicaron una disparidad entre las zonas de manejo y los requerimientos de hábitat de las especies. La zona de manejo se incluyó dentro del modelo final para todas las especies objetivo y la mayoría de ellas tuvo una presencia más alta en las zonas núcleo en relación con las zonas de menor protección. Cuando la zona de manejo se asoció a la presencia de especies simpátricas, las especies amenazadas generalmente tuvieron un mayor número de detecciones en la zona núcleo, mientras que las especies comunes tuvieron un número más elevado de detecciones fuera de la zona núcleo. Nuestros resultados sugieren que la planeación de reservas basada en las especies bandera no protege adecuadamente a las especies simpátricas debido a sus requerimientos especializados de hábitat. Recomendamos una reexaminación de la efectividad del manejo de zonación y urgimos que se genere un plan de monitoreo multiespecífico en toda la reserva para mejorar la protección de la fauna en China. 旗舰物种被广泛地作为伞护物种 (指活动范围广、对其投人的保护措施能够同时有益于其它同域分布物 种的物种) 用于中国自然保护区的管理。旗舰种和伞护种概念的混淆最为突出地体现在, 选择以大熊猫为代表 的大型濒危兽类作为主要保护对象来确定保护区的选址和规划。很少有实证性的研究来检验伞护种是否能有效 代表同域分布物种的保护需求。我们基于大数据量的红外相机调查, 评估了中国 4 个野生动物保护区 (古田山、 长青、老河沟和卧龙) 针对旗舰物种 ( 即主要保护对象) 划定的管理分区对同域分布物种保护的有效性。我们分 析了从保护区实验区向缓冲区、核心区过渡的过程中, 主要保护对象和其它同域分布物种是否均表现出更强的 选择性。多个物种在保护区各个分区内的分布格局显示, 管理分区和物种的栖息地需求并不一致。分区是影响 主要保护对象分布的因素之一。相比实验区和缓冲区, 多数保护对象更多地出现在核心区。然而, 分区对绝大多 数同域分布物种而言, 并不是一个影响其分布的显著因素。对于部分分布受分区影响的同域分布物种而言, 受 威胁物种通常偏好核心区内的生境, 而常见种则偏好实验区内的生境。我们的研究结果表明, 旗舰物种通常有 特化的栖息地需求, 将它们作为同域分布物种的代表以指导保护区规划, 并不能有效保护其它同域分布物种。 我们建议保护区应重新评估管理分区的有效性, 并采用基于多物种的、覆盖保护区全境的监测方案, 以促进对 中国野生动物的有效保护。

Motion-triggered camera traps are subject to imperfect detection and thus camera-trapping surveys often try to increase species detectability as part of the study design. One possible way to increase detectability is to use lures, which may encourage a species to investigate a given area. Yet the effectiveness of lures is primarily grounded in anecdotal support. We quantified the effect of a common olfactory carnivore lure on the detectability of mammals near Chicago, Illinois, USA, during 27 August 2018–25 September 2018. We deployed 2 camera traps per site, spaced apart by 100 m, to assess whether lure can modify detectability both within and between sites. At each camera location, we changed lure treatments every 7 days and placed either a lure or a non-lure control in view of each camera following a fully crossed design. For analysis, we developed single-season occupancy models with 3 distinct observational models to quantify whether lure increased the number of days a species was detected, decreased the amount of time to first detection, and increased the number of images collected. Lure induced a subtle change in detectability. Virginia opossum (Didelphis virginiana) responded most to the presence of lure; their daily detection probability rose by roughly 5% and the number of opossum images nearly doubled. However, the effect of lure was often negative for prey species. When lure was present, eastern cottontail (Sylvilagus floridanus) daily detection probability decreased by 5% and they were photographed 63% less often. Likewise, eastern gray squirrel (Sciurus carolinensis) arrived 70% later to a camera trap if lure was present and were photographed 14% less. By using multiple criteria, we were able to better understand how wildlife respond to lure while camera-trapping more thoroughly than would be possible with a single metric. Our results show that lure may not be as effective as expected in terms of increasing detectability, but the choice to use lure should depend on several factors, including the density of the study species, species life history, and the dynamics between the species studied.

1. Carbon-based policies provide powerful opportunities to unite tropical forest conservation with climate change mitigation. However, their effectiveness in delivering biodiversity co-benefits is dependent on high levels of biodiversity being found in high carbon areas. Previous studies have focussed solely on the co-benefits associated with Reducing Emissions from Deforestation and forest Degradation (REDD+) over large spatial scales, with few empirically testing carbon-biodiversity correlations at management unit scales appropriate to decision-makers. Yet, in development frontiers, where most biodiversity and carbon loss occurs, carbon-based policies are increasingly driven by commodity certification schemes, which are applied at the concession level. 2. Working in a typical human-modified landscape in Southeast Asia, we examined the biodiversity value of land prioritised via application of REDD+ or the High Carbon Stock (HCS) approach, the emerging land-use planning tool for oil palm certification. Carbon stocks were estimated via low- and high-resolution datasets derived from global or local-level biomass. Mammalian species richness was predicted using hierarchical Bayesian multispecies occupancy models of camera-trap data from forest and oil palm habitats. 3. At the community level, HCS forest supported comparable mammal diversity to control sites in continuous forest, while lower carbon strata exhibited reduced species occupancy. 4. No association was found between species richness and carbon when the latter was estimated using coarse-resolution data. However, when using high-resolution, locally validated biomass data, diversity demonstrated positive relationships with carbon for threatened and disturbance-sensitive species, suggesting sensitivity of co-benefits to carbon data sources and the species considered. 5. Policy implications. Our work confirms the potential for environmental certification and Reducing Emissions from Deforestation and forest Degradation to work in tandem with conservation to mitigate agricultural impacts on tropical forest carbon stocks and biodiversity. Successful implementation of both approaches could be used to direct development to low carbon, low biodiversity areas in tropical countries.

Before environmental DNA (eDNA) can establish itself as a robust tool for biodiversity monitoring, comparison with existing approaches is necessary, yet is lacking for terrestrial mammals. Moreover, much is unknown regarding the nature, spread and persistence of DNA shed by animals into terrestrial environments, or the optimal experimental design for understanding these potential biases. To address some of these challenges, we compared the detection of terrestrial mammals using eDNA analysis of soil samples against confirmed species observations from a long-term (approx. 9-year) camera-trapping study. At the same time, we considered multiple experimental parameters, including two sampling designs, two DNA extraction kits and two metabarcodes of different sizes. All mammals regularly recorded with cameras were detected in eDNA. In addition, eDNA reported many unrecorded small mammals whose presence in the study area is otherwise documented. A long metabarcode (≈220 bp) offering a high taxonomic resolution, achieved a similar efficiency as a shorter one (≈70 bp) and a phosphate buffer-based extraction gave similar results as a total DNA extraction method, for a fraction of the price. Our results support that eDNA-based monitoring should become a valuable part of ecosystem surveys, yet mitochondrial reference databases need to be enriched first.

The current decline of mammals worldwide makes quantitative population assessments crucial, especially for range‐restricted and threatened species. However, robust abundance estimations are challenging for elusive or otherwise difficult to detect species. Alternative metrics requiring only presence/absence data, that is, occupancy, are possible but calibration with independent density estimates should be foreseen, although rarely performed. Here, we calibrated density estimates from acoustic surveys to occupancy estimates from camera‐trapping detections to derive the abundance of the endangered Sanje mangabey (Cercocebus sanjei) across its entire range in the Udzungwa Mountains of Tanzania. We found marked occupancy–density relationships for the two forest blocks where this primate occurs and used them to derive spatially explicit density estimates. Occupancy increased in montane forest zones at mid‐elevation but decreased slightly with proximity to forest borders. We predicted an average density (±SE) of 0.26 ± 0.05 groups/km2 in the national park and 0.24 ± 0.06 in the nature reserve. Accordingly, and given the much larger area of the reserve, the average predicted individual abundance was 1555 ± 325 and 2471 ± 571 in the national park and nature reserve, respectively. We found higher density and abundance in the nature reserve compared with previous studies. Given the past disturbance and poorer protection in the nature reserve relative to the national park, our results instill optimism for the status of the species, although occupancy analysis highlighted the potential vulnerability of this primate to human disturbance. Our approach appears valuable for spatially explicit density estimations of elusive species, and provides robust assessments of vulnerability and identification of priority areas for conservation of threatened populations.