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The Javan slow loris Nycticebus javanicus is threatened by habitat decline and is classified as Critically Endangered on the IUCN Red List. Information on its distribution and habitat preferences is still lacking, and so far the distribution of the Javan slow loris has only been quantified via ecological niche modelling based on museum specimens and remotely derived environmental layers. We aimed to refine the modelled predictions and to verify the distribution of the Javan slow loris by collecting up-to-date occurrence data, which are fundamental for conservation and management of the species. Furthermore, we identify variables that predict its presence and give recommendations for future survey sites and conservation actions. From April to June 2012 we collected data on species presence, habitat preferences and levels of disturbance at priority sites throughout Java. We present a map of the predicted distribution of N. javanicus based on a maximum entropy model. We investigated habitat preferences using R (v. 2.14.1). During the study we sighted 52 lorises in 9 out of 14 investigated areas. The amount of bamboo in a forest had a positive effect on the encounter rates. Furthermore, we made 86% of sightings in forest plantations and agricultural areas located outside protected areas, with the majority located in areas with measured high levels of disturbance. We suggest that further ecological studies are needed to understand if and why densities may be higher in anthropogenically disturbed areas.

Simple SummaryWe investigated the niche separation of four macaque species (Macaca arctoides, M. assamensis, M. leonina, M. mulatta) occurring within Nakai-Nam Theun National Protected Area, central-eastern Laos using the environmental niche modelling software MaxEnt. The respective suitable habitat predicted for each species reveals niche segregation between the four species with a gradual geographical distribution following an environmental gradient of, notably, temperature, precipitation, elevation and slope within the study area. This means that the four species seem adapted to different ecological conditions within the area. This information has implications for future research on these species and for their management and conservation.AbstractSpecies misidentification often occurs when dealing with co-existing and morphologically similar species such as macaques, making the study of their ecology challenging. To overcome this issue, we use reliable occurrence data from camera-trap images and transect survey data to model their respective ecological niche and potential distribution locally in Nakai-Nam Theun National Protected Area (NNT NPA), central-Eastern Laos. We investigate niche differentiation of morphologically similar species using four sympatric macaque species in NNT NPA, as our model species: rhesus Macaca mulatta (Taxonomic Serial Number, TSN 180099), Northern pig-tailed M. leonina (TSN not listed); Assamese M. assamensis (TSN 573018) and stump-tailed M. arctoides (TSN 573017). We examine the implications for their conservation. We obtained occurrence data of macaque species from systematic 2006–2011 camera-trapping surveys and 2011–2012 transect surveys and model their niche and potential distribution with MaxEnt software using 25 environmental and topographic variables. The respective suitable habitat predicted for each species reveals niche segregation between the four species with a gradual geographical distribution following an environmental gradient within the study area. Camera-trapping positioned at many locations can increase elusive-species records with a relatively reduced and more systematic sampling effort and provide reliable species occurrence data. These can be used for environmental niche modelling to study niche segregation of morphologically similar species in areas where their distribution remains uncertain. Examining unresolved species’ niches and potential distributions can have crucial implications for future research and species’ management and conservation even in the most remote regions and for the least-known species.

Species distribution models are a key component for understanding a species' potential occurrence, specifically in vastly undersampled landscapes. The current species distribution data for the Assamese macaque Macaca assamensis are outdated, but suggest a patchy distribution in moist broadleaved forests in South and Southeast Asia. Therefore, in this study, we used a species distribution model to explore the potential climatic niche of this species and assess its distribution and potential barriers in 12 South and Southeast Asian countries. We combined primary and secondary species occurrence records from different countries. We applied Classification and Regression Tree (CART), TreeNet (boosting), RandomForest (bagging) and Maximum Entropy (MaxEnt) machine-learning algorithms with elevation as well as 19 bioclimatic variables for the first ensemble predictions ever completed for this species. Our results suggested that the predicted distribution of the Assamese macaque is strongly associated with precipitation of warmest quarter (BIO18), temperature annual range (BIO7) and temperature seasonality (BIO4). Our prediction shows a continuous potential climatic niche of the species from east of the Kaligandaki River in Nepal to Lao People's Democratic Republic. There are also potential niche patches in Bhutan, Southeast China, Thailand and Cambodia, while Pakistan and Afghanistan have no potential niche for the species. We believe that our workflow presents a new conservationoriented open access research template to progress empirical primate conservation worldwide.

The endangered red-shanked douc (Pygathrix nemaeus), endemic to Lao PDR, Vietnam, and perhaps Cambodia, remains little known. The Lao population is highly threatened. To improve conservation prospects of the species there, we here update a status review from 1999. Subsequent literature (mostly not readily available to the outside scientific community) was reviewed critically. Doucs and their habitat in Lao PDR faced continuous, increasing threats in the past 10 years through large development projects and heavy hunting. Many locations with records from the 1990s were not surveyed in the last decade, so douc persistence remains uncertain in them. Given the poor status of the species in Vietnam and Cambodia, the Lao population is surely the world's largest and the best hope for the species' global conservation. Resources for conserving species are very limited in the country, urging prioritization of populations, so available resources have maximum effect. Nakai-Nam Theun and Hin Namno National Protected Areas hold the largest populations of P. nemaeus, but face great threats from hunting. Management of these areas (and secondary priority areas) should focus on control of this illegal activity.

The Endangered red-shanked douc Pygathrix nemaeus is a charismatic Asian colobine endemic to Vietnam, Cambodia and Lao People's Democratic Republic (PDR). The largest population is found in central-eastern Lao PDR but it has never been quantified. We conducted line-transect surveys in Nakai-Nam Theun National Protected Area in 2011-2012. We used distance sampling combined with a habitat suitability model to estimate group density and group abundance in the area. Our analysis yielded a density of 2.8 (range 1.9-4.1) groups per km 2 and c. 4,420 groups within the predicted c. 1,600 km 2 of suitable habitat in Nakai-Nam Theun. These are the only available data for P. nemaeus in Lao PDR to date. We discuss the limitations of our survey, which involved potential violations of the distance sampling method, and highlight the challenges of using this method for primates. We also consider the importance of assessing limitations in distance sampling studies, to evaluate reliability and facilitate comparisons. The population of P. nemaeus in Lao PDR is under threat from illegal hunting and is not the focus of any specific conservation action. To avoid a repetition of the decline the species has already experienced in Vietnam, and to secure the species' global survival, conservation projects need to target the population in Nakai-Nam Theun. A long-term conservation and research project in this key biodiversity area will also benefit other threatened and unique co-existing species.Result for primary hill forest survey, estimated using effective distance method (Whitesides et al., 1988) Conservation of red-shanked doucs in Lao PDR

We conducted a primate survey in Samkos Wildlife Sanctuary, western Cambodia, during the wet season in 2009. We visually confirmed the presence of five out of six primate species thought to occur in the area: Bengal slow loris Nycticebus bengalensis, Indochinese silvered langur Trachypithecus germaini, pileated gibbon Hylobates pileatus, pig-tailed macaque Macaca leonina and long-tailed macaque Macaca fascicularis. We did not find any sign of the stumptailed macaque Macaca arctoides and suggest it is absent in Samkos Wildlife Sanctuary and possibly from the Cardamom Mountains. We provide the abundance measures for each primate species; the three most abundant species were Bengal slow loris, Indochinese silvered langur and pileated gibbon. We propose Samkos Wildlife Sanctuary as a priority for primate conservation in Cambodia.

The Annamites ecoregion harbors exceptional levels of species richness and endemism, but intensive snaring has decimated populations of terrestrial mammals. Ungulates, such as muntjacs, are susceptible to snaring, and in need of effective conservation action. At least three muntjacs occur sympatrically in the region: the Annamite dark muntjac species complex Muntiacus rooseveltorum/truongsonensis, the northern red muntjac Muntiacus vaginalis, and the large-antlered muntjac Muntiacus vuquangensis. We conducted a landscape-scale systematic camera-trapping survey in Nakai-Nam Theun National Park to gather information on the ecology and distribution of these muntjacs. We analyzed camera-trap records within an occupancy framework to evaluate responses to environmental and anthropogenic variables, and to predict distributions across the protected area. We found varying responses to the covariates, indicating complex drivers of occurrence, though all three muntjac had higher occupancies in more inaccessible areas. Mean (95%) PAO in the protected area was higher for large-antlered muntjac (0.33 [0.22–0.49]), followed by Annamite dark muntjac (0.28 [0.18–0.39]), and then northern red muntjac (0.27 [0.15–0.42]). Large-antlered muntjac and northern red muntjac were widespread, while dark muntjac was restricted to a single high elevation area. Overall, our results provide new insights into muntjac ecology, distribution, and population status, and we discuss how this information can be used to inform conservation efforts. Given the high occupancies that we found for the Critically Endangered large-antlered muntjac, we argue that Nakai-Nam Theun National Park may be vital for the long-term survival of the species.