Pongo pygmaeus pygmaeus is a subspecies of Bornean orangutan whose distribution is restricted to the northern part of the Kapuas River, West Kalimantan, and is categorized as Critically Endangered. In October 2017 we carried out a survey to estimate orangutan density in the peat-swamp forests of the Sungai Palin watershed, of the upper Kapuas river, Kapuas Hulu, West Kalimantan, Indonesia. Surveys for orangutans in 1991, in nearby Nanga Awen, had indicated the presence of orangutans in the peat-swamp forests of this area. We used distance sampling techniques to estimate orangutan densities from nest observations. We recorded 76 orangutan nests along 4.5 km transects in Sungai Palin in 2017, and 71 orangutan nests were observed along 4.3 km transects in Nanga Awen in 1991, giving densities of 1.29 and 2.62 individuals/km2, respectively. The results of this orangutan survey can be used as a baseline for monitoring of orangutan populations for conservation and management of this watershed landscape.

All gibbon species are declining throughout South and South-east Asia because of habitat loss and human activities such as hunting. Lao still contains a relatively large area of forest habitat suitable for gibbons, but their status in the country remains poorly known. Here we present the first density estimate of the Critically Endangered northern white-cheeked gibbon Nomascus leucogenys in Nam Et-Phou Louey National Protected Area, northern Lao. We conducted gibbon surveys using an auditory sampling technique during May–August 2014 and May 2015, at 40 sites, covering 125.6 km2. We applied N-mixture models to analyse group counts, investigating which landscape and human disturbance covariates influenced the spatial variation of gibbon abundance across the study area. We estimated the average gibbon density to be 0.4 groups/km2. Gibbon density was higher in mixed deciduous forest (0.74 groups/km2) than in evergreen forest (0.09 groups/km2), which could be a result of long-term hunting in evergreen forest areas. Thus, future gibbon protection plans should consider not only evergreen forest as priority habitat, but also deciduous forest, which tends to receive less attention in conservation planning. We also highlight key areas containing gibbons where law enforcement patrols should be focussed, to limit threats such as poaching. Future forest management plans should aim to maximize the size and connectivity of suitable gibbon habitat, to enable exchange between subpopulations.

The cao vit gibbon Nomascus nasutus, also known as eastern black crested gibbon, is categorized as Critically Endangered on the IUCN Red List and was considered one of the world's 25 most threatened primates. The only known population occurs along the border between China and Viet Nam. Accurate information on population size and dynamics is critical for the species’ conservation, but population surveys conducted in only one country may over- or underestimate total population size because the home ranges of cao vit gibbon groups often cross the international border. In 2007 and 2016 we conducted two collaborative transboundary censuses of the cao vit gibbon populations in the Trung Khanh Cao Vit Gibbon Species and Habitat Conservation Area in Viet Nam and the Bangliang Gibbon National Nature Reserve in China. The results showed a population size of 102–110 in 2007, which increased to 107–136 in 2016. Our results indicate that previous surveys conducted separately in Viet Nam and China underestimated the global population size of this species. According to our more comprehensive surveys, the gibbon population is increasing slowly. The gibbons and their habitat are legally protected in both countries. Hunting and charcoal making have not been reported in this area since 2007. As habitat carrying capacity is a limiting factor, habitat restoration is required. However, lack of funding to protect the cao vit gibbon remains a challenge.

Primates are one of the most threatened groups of mammals. Understanding their patterns of population occurrence and abundance, especially in response to threats, is critical for informing conservation action. The crested black macaque Macaca nigra is the only Critically Endangered species of Sulawesi's seven endemic macaques. Little is known about its distribution or its response to deforestation and hunting. We conducted a camera-trap survey across the entire species range using an occupancy-based analytical approach to (1) establish the first range-wide baseline of occurrence, (2) investigate how environmental and anthropogenic factors influence occurrence, (3) identify priority conservation subpopulations, and (4) test the efficacy of the sampling and analytical protocol for temporal monitoring of M. nigra using occupancy as the state variable. From 9,753 camera-trap days, M. nigra was detected on 473 days at 77 of the 111 camera locations. Species occupancy was 0.66 and highest inside protected areas and closed canopy forest. We identified eight distinct subpopulations, based on distribution and forest fragment size. To inform future monitoring, we used a power analysis to determine if our effort would allow us to detect inter-annual occupancy declines of 10%, and found that 90 camera locations surveyed for 3 months (8,100 camera days) across three consecutive seasons is the effort required to detect such change with 80% certainty. Our study underscores the importance of well-managed protected areas and intact forests for the long-term survival of the crested black macaque, and tests the effectiveness of camera traps to monitor primates at the landscape scale.

The Caatinga of north-eastern Brazil is the largest and most diverse seasonally dry tropical forest in the Americas and is home to numerous endemic species. However, only 1.2% of the area is under full protection, and given the ongoing decline of this biome there is an urgent need to expand the protected area network. The Endangered Caatinga howler monkey Alouatta ululata is almost endemic to the Caatinga, and is a potential umbrella species for the protection of its biodiversity. Using all available distribution data and our own surveys we applied Maxent and Zonation spatial modelling to identify the range of A. ululata, and priority conservation areas for the species, maximizing habitat quality and connectivity, and minimizing conservation constraints. The top 10% priority areas cover 34,400 km2 and mostly coincide with good remnants of Caatinga. Only priority areas in the northern part of the species’ range are protected, so it is essential to create new protected areas in the centre and south of the range. Maxent modelling indicates that the species depends on good tree cover, but even inside protected areas we observed recent deforestation, illustrating the urgency to improve management. Maxent also indicated that aridity limits the species' range, and therefore the ongoing aridification of the Caatinga is a threat to its future. The protection of A. ululata requires establishing new protected areas in priority locations and improving management of existing protected areas. Preservation of priority areas for the Caatinga howler monkey also represents an opportunity for the conservation of other important biodiversity in the region.

Brazil has a high diversity of primates, but increasing anthropogenic pressures and climate change could influence forest cover in the country and cause future changes in the distribution of primate populations. Here we aim to assess the long-term suitability of habitats for the conservation of three threatened Brazilian primates (Alouatta belzebul, Sapajus flavius and Sapajus libidinosus) through (1) estimating their current and future distributions using species distribution models, (2) evaluating how much of the areas projected to be suitable is represented within protected areas and priority areas for biodiversity conservation, and (3) assessing the extent of remaining forest cover in areas predicted to be suitable for these species. We found that 88% of the suitable areas are outside protected areas and only 24% are located in areas with forest cover. Although not within protected areas, 27% of the climatically suitable areas are considered priority areas for conservation. Future projections, considering a severe climate change scenario, indicate that A. belzebul, S. flavius and S. libidinosus may lose up to 94, 98 and 54% of their suitable range, respectively. The establishment of primate populations and their long-term survival in these areas are at risk. Mitigation actions such as the implementation of new protected areas, forest restoration and reduction of greenhouse gas emissions will be essential for the conservation of Brazilian primates.

The Critically Endangered Peruvian yellow-tailed woolly monkey Lagothrix flavicauda was presumed to only occur in the tropical montane cloud forests between the Marañón and Huallaga rivers in northern Peru. Here we report the discovery of a population to the south of its previously known range, in the Región Junín. During September–December 2018 we carried out transect surveys to record large mammals present near the village of San Antonio in the district of Pampa Hermosa, at 1,287–2,015 m altitude. We recorded five primate species during transect surveys. Lagothrix flavicauda was seen four times, and appeared phenotypically distinct from populations to the north, with notable white patches above each eye and a reduced yellow patch at the end of the tail. The presence of L. flavicauda in Junín extends its known geographical range over 200 km southwards from the closest previously known population in the Huánuco region, and presents a unique opportunity for the conservation of this Critically Endangered species.

The Critically Endangered blue-eyed black lemur Eulemur flavifrons of north-western Madagascar is one of the most threatened primates. The majority of research and conservation efforts for the species have been restricted to the Sahamalaza Peninsula but there are unstudied and unprotected populations farther inland. The dearth of information regarding the transition between E. flavifrons and its parapatric sister species, the Vulnerable black lemur Eulemur macaco, and the possibility of a hybrid population complicates conservation planning for both species. We surveyed 29 forest fragments across both species’ ranges to investigate the boundary between the taxa, whether hybrids persist, and the threats to lemurs in the region. We found E. flavifrons in six fragments and E. macaco in 17. We never observed E. flavifrons and E. macaco in the same location and we found no conclusive evidence of hybrids. Three fragments in which E. flavifrons was present were north of the Andranomalaza River, which had previously been considered the barrier between the two species. Based on these observations and a literature review, we provide updated ranges, increasing the extent of occurrence (EOO) of E. flavifrons by 28.7% and reducing the EOO of E. macaco by 44.5%. We also evaluate the capacity of protected areas to conserve these lemurs. We recommend additional surveys and the implementation of an education programme in this region to help conserve both species.

Anthropogenic habitat alteration and invasive species are threatening carnivores globally. Understanding the impact of these factors is critical for creating localized, effective conservation programmes. Madagascar's Eupleridae have been described as the least studied and most threatened group of carnivores. We investigated the effects of habitat degradation and the presence of people and exotic species on the modelled occupancy of the endemic fosa Cryptoprocta ferox, conducting camera-trap surveys in two western deciduous forests, Ankarafantsika National Park and Andranomena Special Reserve. Our results indicated no clear patterns between habitat degradation and fosa occupancy but a strong negative association between cats Felis sp. and fosas. Cat occupancy was negatively associated with birds and positively associated with contiguous forest and narrow trails. In contrast, dog Canis lupus familiaris occupancy was best predicted by wide trails, degraded forest and exotic civets. Our results suggest fosas are capable of traversing degraded landscapes and, in the short term, are resilient to contiguous forest disturbance. However, high occupancy of cats and dogs in the landscape leads to resource competition through prey exploitation and interference, increasing the risk of transmission of potentially fatal diseases. Management strategies for exotic carnivores should be considered, to reduce the widespread predation of endemic species and the transmission of disease.

The Vulnerable fosa Cryptoprocta ferox is the largest native carnivore in Madagascar, fulfilling a unique ecological niche in the island's remaining forests. Negative interactions with humans threaten the long-term viability of most remaining fosa populations across Madagascar. Threats to the fosa include habitat loss and persecution by humans resulting from perceived predation on domestic animals. We used GPS collars to record space use and activity patterns of five fosas in Ankarafantsika National Park, Madagascar, during the dry seasons of 2016 and 2017. The results, with up to 2,110 recorded locations per individual, indicated fosas’ home ranges and movements were not limited to the forest, and all collared individuals used networks of habitat patches and corridors to navigate deforested areas. The fosas studied in Ankarafantsika National Park had significantly larger home ranges than those reported in previous studies in other protected areas. They were rarely found within village boundaries and appeared to avoid areas of human habitation, suggesting that during the study period livestock was not a significant component of the fosas’ diet in this Park. Our results suggest that fosas have some flexibility that enables them to adapt to living near deforested and human-dominated areas by altering their space-use patterns, but they are compensating by increasing their home range size.

Globally, little is known about the dispersal abilities of carnivores, their survival in non-protected areas, and the connectivity between protected and non-protected populations. More than a decade of sighting data for 496 known African lions Panthera leo, with 189 individuals engaging in dispersing activities plus an exchange of cross-site information, has provided unique insight into connectivity and survival in unprotected and protected areas in Kenya. In particular, three individuals, across two generations residing solely in unprotected landscapes, demonstrated connectivity between three protected areas that, to our knowledge, have not previously been recognized as harbouring connected populations. These observations suggest that unprotected areas and the human communities that reside in them may successfully create corridors of tolerance that facilitate connectivity and the long-term persistence of lion populations, both within and outside protected areas.

The civil unrest that ravaged Angola for nearly 30 years took a heavy toll on the country's wildlife, and led to a lengthy absence of reliable information for many threatened species, including the cheetah Acinonyx jubatus and African wild dog Lycaon pictus. Using camera trapping we assessed the status of these two species in two areas of southern Angola, and complemented our findings by reviewing recent survey reports and observations to provide an update on the species' status. We found unequivocal evidence that African wild dogs are resident and reproducing in Bicuar National Park, where cheetahs appear to be absent. Conversely, cheetahs may be resident in western Cuando Cubango province, where African wild dogs may only be transient. Based on these and other recent records in Angola, we recommend a revision of these species' distribution ranges and note the need for monitoring of these remnant populations and for appropriate attention to any threats.

The jaguar Panthera onca, a threatened species in Brazil, is losing suitable habitat as a result of agricultural expansion and other forms of land conversion, especially in the Cerrado biome. In the current context of habitat loss and fragmentation, a network of protected areas is paramount for the conservation of this species. We aimed to identify jaguar conservation units in the Cerrado, and propose a ranking of priority areas for the species in this region. We used the maximum entropy algorithm to model habitat suitability for the jaguar in the Cerrado, with nine uncorrelated environmental variables and 106 non-autocorrelated presence-only records. We prioritized regions, using Zonation, and ranked jaguar conservation units according to their area, proximity to strictly protected areas, jaguar presence, and potential for connectivity. Circa 30% of the Cerrado is suitable for the jaguar. The most important variables affecting jaguar distribution are mean rainfall and land cover, with a high probability of jaguar presence in forest and savannah. We selected 31 high-priority jaguar conservation units, covering c. 174,825 km2 (8.5%) of the Cerrado. We emphasize the need for new protected areas and the promotion of sustainable development, as only 0.4% of the Cerrado (8,345 km2) has high environmental suitability for jaguars and < 1% of the area covered by jaguar conservation units falls within protected areas. Most jaguar conservation units identified here are relevant for habitat connectivity in Brazil, given their proximity to other critical areas for jaguar conservation in the Caatinga and the Amazon.