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The scope, scale, and socio-environmental impacts of wildlife crime pose diverse risks to people, animals, and environments. With direct knowledge of the persistence and dynamics of wildlife crime, protected area rangers can be both an essential source of information on, and front-line authority for, preventing wildlife crime. Beyond patrol and crime scene data collected by rangers, solutions to wildlife crime could be better built off the knowledge and situational awareness of rangers, in particular rangers' relationships with local communities and their unique ability to engage them. Rangers are often embedded in the communities surrounding the conserved areas which they are charged with protecting, which presents both challenges and opportunities for their work on wildlife crime prevention. Cultural brokerage refers to the process by which intermediaries, like rangers, facilitate interactions between other relevant stakeholders that are separate yet proximate to one another, or that lack access to, or trust in, one another. Cultural brokers can function as gatekeepers, representatives, liaisons, coordinators, or iterant brokers; these forms vary by how information flows and how closely aligned the broker is to particular stakeholders. The objectives of this paper are to use the example of protected area rangers in Viet Nam to (a) characterize rangers' cultural brokerage of resources, information, and relationships and (b) discuss ranger-identified obstacles to the prevention of wildlife crime as an example of brokered knowledge. Using in-depth face-to-face interviews with rangers and other protected area staff (N = 31, 71% rangers) in Pu Mat National Park, 2018, we found that rangers regularly shift between forms of cultural brokerage. We offer a typology of the diverse forms of cultural brokerage that characterize rangers' relationships with communities and other stakeholders. We then discuss ranger-identified obstacles to wildlife protection as an example of brokered knowledge. These results have implications for designing interventions to address wildlife crime that both improve community-ranger interactions and increase the efficiency of wildlife crime prevention.

AimUnsustainable 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.LocationAnnamite mountains, Vietnam and Laos.MethodsWe conducted systematic landscape-scale surveys across five study sites (four protected areas, one unprotected area) using camera-trapping and leech-derived environmental DNA. We analyzed detections within a Bayesian multi-species 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.ResultsAnalyses 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 conclusionIdentifying spatial patterns of biodiversity in heavily-defaunated landscapes may require novel methodological and analytical approaches. Our results indicate 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 analyze data within a Bayesian multi-species 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.

Information on geographic patterns of species genetic diversity is often needed to inform conservation strategies. Obtaining data over large geographic areas can be difficult, especially for rare or elusive species. Here, we explore the use of invertebrate‐derived DNA (iDNA) obtained from terrestrial leeches to assess genetic diversity of the Annamite striped rabbit Nesolagus timminsi, a little‐known and highly threatened lagomorph endemic to the Annamites ecoregion of Vietnam and Laos. We collected 4,877 leeches pooled into 651 leech bulk samples from eight study areas across the northern and central Annamites. Using metabarcoding, we detected Annamite striped rabbit DNA in 11 leech bulk samples from five of the study areas. We amplified up to 3,000 bp of six mitochondrial DNA loci of Annamite striped rabbit from nine of the 11 bulk samples. Haplotype network analyses showed five shared haplotypes among these samples. Phylogenetic trees constructed using maximum likelihood and Bayesian inference showed little geographic structuring among the Annamite striped rabbit populations across the five study areas. Our results provide information that can be directly used to inform planned ex situ conservation measures for the Annamite striped rabbit. We discuss our results within the context of using iDNA to noninvasively obtain data to assess species genetic diversity, and the potential of this approach to be applied to other species and systems.

Poaching can contribute to the failure of biodiversity conservation efforts and inflict diverse harms on human livelihoods. We applied crime script analysis to the case of snare poaching—an illegal hunting activity—in three Vietnamese protected areas. Our goal was to enhance the understanding about the opportunity structure underlying snare poaching to advance the suite of community-based crime prevention activities. We analyzed crime scripts for three types of poachers across nine stages of the poaching process using expert-based elicitation with 13 workshop participants in Vinh, Vietnam, 2018. Five stages were similar, clustered toward the early stages, and two were different, clustered around middle crime stages. Analysis produced systematic crime-specific insight about the procedural aspects and requirements for poaching from preparation to hunt to selling one’s catch. Stages identify multiple entry points to apply prevention techniques and match techniques with different types of snare poaching or poachers. Although this research focused on protected areas, the interdisciplinary approach applied herein may be adapted to other conservation contexts.

Primate home range size and habitat use are affected by resource availability, which may change seasonally. Limestone langurs (Trachypithecus genus), including the Critically Endangered Cat Ba langur (Trachypithecus poliocephalus), live on limestone karst hills with shrubby and discontinuous vegetation. This study explores home range size and habitat use in relation to substrate, vegetation coverage, and hill type for Cat Ba langurs living on Cat Ba Island. We predicted that home range size would be similar to that of other limestone langurs and that as resources vary seasonally and across habitat types, habitat use would vary with season and behavior, with foraging concentrated on slopes, where food is plentiful. We collected 180 days of observational data on two reproductive groups (N = 7 and N = 10–13), taking GPS fixes of the group whenever they moved farther than the typical group spread to determine home ranges, and 10-min instantaneous scans to assess habitat use. The two groups had home ranges of 22 ha and 50 ha (0.32 and 0.20–0.26 individuals/ha respectively). Ranges for both groups were smaller in the dry season than the wet season, although we could not assess seasonal variation statistically. The langurs spent most scans on rocks, in sparsely vegetated areas, and on exposed slopes and steep cliffs; however they foraged primarily on gradually inclined slopes, especially in the dry season. These results suggest that conservation efforts should focus on protecting nutritionally important valleys and exposed slopes to ensure year-long access to food resources. It may, however, be difficult to balance human and nonhuman primate habitat use.

Habitat degradation and hunting have caused the widespread loss of larger vertebrate species (defaunation) from tropical biodiversity hotspots. However, these defaunation drivers impact vertebrate biodiversity in different ways and, therefore, require different conservation interventions. We conducted landscape-scale camera-trap surveys across six study sites in Southeast Asia to assess how moderate degradation and intensive, indiscriminate hunting differentially impact tropical terrestrial mammals and birds. We found that functional extinction rates were higher in hunted compared to degraded sites. Species found in both sites had lower occupancies in the hunted sites. Canopy closure was the main predictor of occurrence in the degraded sites, while village density primarily influenced occurrence in the hunted sites. Our findings suggest that intensive, indiscriminate hunting may be a more immediate threat than moderate habitat degradation for tropical faunal communities, and that conservation stakeholders should focus as much on overhunting as on habitat conservation to address the defaunation crisis., Andrew Tilker, Jesse F. Abrams et al. assessed habitat degradation and hunting on tropical terrestrial mammals and birds in Southeast Asia. They find higher levels of functional extinction and consistently lower animal occupancy in hunted sites, suggesting that indiscriminate hunting is a more immediate threat for tropical animal communities.

All gibbon species (Family: Hylobatidae) are considered threatened with extinction and recognized on the International Union for Conservation of Nature Red List of Threatened Species. Because gibbons are one of the most threatened families of primates, monitoring their status is now critically important. Long-term monitoring programs applying occupancy approaches, in addition to assessing occurrence probability, improves understanding of other population parameters such as site extinction or colonization probabilities, which elucidate temporal and spatial changes and are therefore important for guiding conservation efforts. In this study, we used multiple season occupancy models to monitor occurrence, extinction, and colonization probabilities for northern yellow-cheeked crested gibbon Nomascus annamensis in three adjacent protected areas in the Central Annamites mountain range, Vietnam. We collected data at 30 listening posts in 2012, 2014, and 2016 using the auditory point count method. Occurrence probabilities were highest in 2012 (0.74, confidence interval [CI]: 0.56-0.87) but slightly lower in 2014 (0.66, CI: 0.51-0.79) and 2016 (0.67, CI: 0.49-0.81). Extinction probabilities during the 2012-2014 and 2014-2016 intervals were 0.26 (0.14-0.44) and 0.25 (0.12-0.44), respectively. Colonization probabilities during 2012-2014 were 0.44 (0.19-0.73) and between 2014 and 2016 was 0.51 (0.26-0.75). Although local site extinctions have occurred, high recolonization probability helped to replenish the unoccupied sites and kept the occurrence probability stable. Long-term monitoring programs which use occurrence probability alone might not fully reveal the true dynamics of gibbon populations. We strongly recommend including multiple season occupancy models to monitor occurrence, extinction, and colonization probabilities in long-term gibbon monitoring programs.

Primate activity budgets are dictated by food availability and distribution; thus primates living in seasonal environments must adapt their behaviors to accommodate fluctuations in resources. Cat Ba langurs (Trachypithecus poliocephalus), a Critically Endangered Asian colobine and a member of the limestone langur group (francoisi superspecies group within genus Trachypithecus), live only in fragmented and disturbed habitats on Cat Ba Island, northeastern Vietnam. This study aimed to assess the behaviors and diet of Cat Ba langurs by group, age, sex, and season. We predicted they would have high rates of inactivity and foraging, low rates of social behaviors, with seasonal variation that reflects an energy-maximizing strategy. We conducted behavioral observations through scan sampling over an 11-month period and found that Cat Ba langurs spent a significant portion of their day inactive (57 %) followed by foraging (18 %), socializing (13 %), locomoting (10 %), and engaging in “other” behaviors (2 %). Their diet was made up primarily of leaves (83 %) followed by flowers (8 %), fruit (6 %), and stems (3 %). We found groups to differ in diet and activity, which is likely owing to differences in demographics and home range between groups. Seasonally, the animals ate more leaves and spent more time foraging in the dry season than the wet season, suggesting that they are energy maximizers. Cat Ba langurs have activity and dietary budgets similar to those of other limestone langurs, and respond to a presumed seasonal fluctuation in food availability similarly.

D. Kidney was supported by an Engineering and Physical Sciences Research Council (EPSRC) Doctoral Training Grant studentship (EPSRC grant EP/P505097/1). B. Stevenson was supported by a studentship jointly funded by the University of St Andrews and EPSRC, through the National Centre for Statistical Ecology (EPSRC grant EP/I000917/1). Some animal species are hard to see but easy to hear. Standard visual methods for estimating population density for such species are often ineffective or inefficient, but methods based on passive acoustics show more promise. We develop spatially explicit capture-recapture (SECR) methods for territorial vocalising species, in which humans act as an acoustic detector array. We use SECR and estimated bearing data from a single-occasion acoustic survey of a gibbon population in northeastern Cambodia to estimate the density of calling groups. The properties of the estimator are assessed using a simulation study, in which a variety of survey designs are also investigated. We then present a new form of the SECR likelihood for multi-occasion data which accounts for the stochastic availability of animals. In the context of gibbon surveys this allows model-based estimation of the proportion of groups that produce territorial vocalisations on a given day, thereby enabling the density of groups, instead of the density of calling groups, to be estimated. We illustrate the performance of this new estimator by simulation. We show that it is possible to estimate density reliably from human acoustic detections of visually cryptic species using SECR methods. For gibbon surveys we also show that incorporating observers' estimates of bearings to detected groups substantially improves estimator performance. Using the new form of the SECR likelihood we demonstrate that estimates of availability, in addition to population density and detection function parameters, can be obtained from multi-occasion data, and that the detection function parameters are not confounded with the availability parameter. This acoustic SECR method provides a means of obtaining reliable density estimates for territorial vocalising species. It is also efficient in terms of data requirements since it only requires routine survey data. We anticipate that the low-tech field requirements will make this method an attractive option in many situations where populations can be surveyed acoustically by humans. Publisher PDF

With less than 3200 wild tigers in 2010, the heads of 13 tiger-range countries committed to doubling the global population of wild tigers by 2022. This goal represents the highest level of ambition and commitment required to turn the tide for tigers in the wild. Yet, ensuring efficient and targeted implementation of conservation actions alongside systematic monitoring of progress towards this goal requires that we set site-specific recovery targets and timelines that are ecologically realistic. In this study, we assess the recovery potential of 18 sites identified under WWF's Tigers Alive Initiative. We delineated recovery systems comprising a source, recovery site, and support region, which need to be managed synergistically to meet these targets. By using the best available data on tiger and prey numbers, and adapting existing species recovery frameworks, we show that these sites, which currently support 165 (118-277) tigers, have the potential to harbour 585 (454-739) individuals. This would constitute a 15% increase in the global population and represent over a three-fold increase within these specific sites, on an average. However, it may not be realistic to achieve this target by 2022, since tiger recovery in 15 of these 18 sites is contingent on the initial recovery of prey populations, which is a slow process. We conclude that while sustained conservation efforts can yield significant recoveries, it is critical that we commit our resources to achieving the biologically realistic targets for these sites even if the timelines are extended.

Crested gibbons, genus Nomascus, are endemic to the Indochinese bioregion and occur only in Vietnam, Laos, Cambodia, and southern China. However, knowledge about the number of species to be recognized and their exact geographical distributions is still limited. To further elucidate the evolutionary history of crested gibbon species and to settle their distribution ranges, we analyzed the complete mitochondrial cytochrome b gene from 79 crested gibbon individuals from known locations. Based on our findings, crested gibbons should be classified into seven species. Within N. concolor, we recognize two subspecies, N. concolor concolor and N. concolor lu. Phylogenetic reconstructions indicate that the northernmost species, N. hainanus, N. nasutus, and N. concolor branched off first, suggesting that the genus originated in the north and successively migrated to the south. The most recent splits within Nomascus occurred between N. leucogenys and N. siki, and between Nomascus sp. and N. gabriellae. Based on our data, the currently postulated distributions of the latter four species have to be revised. Our study shows that molecular methods are a useful tool to elucidate phylogenetic relationships among crested gibbons and to determine species boundaries. Am. J. Primatol. 72:1047–1054, 2010. © 2010 Wiley-Liss, Inc.

Rehabilitation and translocation programmes are increasingly becoming an important component of conservation action plans for threatened species. Translocation can help address gibbon conservation issues (gibbons are recognized as one of the most threatened primate families globally) by allowing gibbons held in captivity to be rescued, rehabilitated and then returned to the wild. These guidelines for the translocation of gibbons have been developed in collaboration with stakeholders in hylobatid conservation. This process was initiated druing a workshop on gibbon rehabilitation, reintroduction and translocation, facilitated by the IUCN SSC PSG Section on Small Apes (SSA), and the result of this process is the current document, which is based on shared knowledge and experience to date. The guidelines are designed to be a practical and useful document available for all stakeholders, with the aim of equipping field projects and decision makers with the tools for scientifically sound practice in gibbon rehabilitation and translocation.

The yellow-cheeked crested gibbon (Nomascus gabriellae) occurs east of the Mekong River in southern Vietnam, northeastern Cambodia, and possibly southernmost Lao PDR (2000, Nomad RSI unpubl. data). The northern distributional limit is unclear as it either borders or intergrades with the southern white-cheeked crested gibbon,N. siki (Duckworth et al. 1995, 1999; Geissmann et al. 2000; Konrad 2004). N. gabriellae is currently listed as Endangered in the IUCN Red List of Threatened Species (IUCN 2008). Little behavioral or ecological work was conducted on the species until recent years; however, a picture of the species is beginning to emerge with current studies, particularly in the SBCA (Rawson 2004) and Ratanakiri province, Cambodia (Traeholt et al. 2006), and Cat Tien National Park (NP) in Vietnam (M. Kenyon pers. comm.). It appears that N. gabriellae generally prefers undisturbed evergreen forest with a reasonably high canopy (Nguyen Xuan Dang and Osborn 2004; Traeholt et al. 2006) although the species inhabits other habitat types such as semi-evergreen, mixed deciduous, and even bamboo forest (M. Kenyon pers. comm., this paper). The species can apparently survive a reasonably high degree of habitat and incidental disturbance, persisting in selectively logged habitats and close to human habitation when not hunted to extirpation (Duckworth et al. 1999; Polet et al. 2004, BMR and TC pers. obs.). It has wide altitudinal limits, occurring from 100 m above sea level (m asl) in Cat Tien NP (Eames and Robson 1993) to above 2000 m asl on the Da Lat plateau, Vietnam (Eames and Nguyen Cu 1994). N. gabriellae, like other gibbon species, is territorial and monogamous (Traeholt et al. 2006), with mated individuals producing loud vocal duets