Since it was first described in 1901, the Príncipe thrush Turdus xanthorhynchus has been rare and restricted to the native forest in the south of Príncipe Island. The Obô giant land snail Archachatina bicarinata, however, was widespread across the island and at least locally abundant until the 1990s. Since then its population has collapsed, and now, like the thrush, it is also restricted to the native forest in the south of the island. Using species distribution modelling, we show that both species are currently strongly associated with rugged and remote areas of native forest at high altitudes. We argue that their current distribution might be negatively affected by anthropogenic pressures, as both are harvested, and also because invasive alien species are expected to have deleterious effects on these species, although further studies are needed to clarify interactions between these native and introduced species. The diachronic stories of these species highlight an overlooked value of native ecosystems: their role in the conservation of widespread species that might be unable to use anthropogenic landscapes in the future. They also reinforce the need for protected areas that strive to exclude most human activities in the context of particularly sensitive biodiversity, as is often the case on oceanic islands.

The gharial Gavialis gangeticus is a Critically Endangered crocodilian endemic to the Indian subcontinent. Habitat modification by river damming and water extraction has caused a severe decline in its population. The status of the gharial is known within protected areas, but there have been few surveys for this species in unprotected areas. In Katerniaghat Wildlife Sanctuary, a breeding gharial population in Girijapuri Barrage Reservoir has low recruitment, and it has been hypothesized that yearlings disperse downstream into the unprotected Ghaghara River when the barrage gates are opened. We surveyed a 100-km stretch of the Ghaghara River from the Girijapuri Barrage to Chahlari Ghat, observing a total of 84 gharials, including a high proportion of juveniles. A survey in 2021 from Chahlari Ghat to Ayodhya observed 174 gharials, giving a combined total of 258 gharials in a 219-km stretch of the Ghaghara River for the two surveys. Together, these findings confirm the presence of a significant population of gharials in the Ghaghara River. We recommend the adoption of an integrated approach, involving government agencies and local communities along the river, to conserve the protected Girwa–Kaudiyala Rivers and the unprotected Ghaghara River for gharial conservation and recovery. Such a programme will need to tackle the threats facing the gharial and establish baseline data and long-term monitoring protocols for freshwater species conservation in this river system.

We present the results of two population surveys conducted 10 years apart (December 2010–February 2011 and December 2020–January 2021) of the Critically Endangered white-headed langur Trachypithecus leucocephalus in the Chongzuo White-Headed Langur National Nature Reserve, Guangxi Province, China. In the first survey, we recorded 818 individuals in 105 groups and 16 solitary adult males. In the second survey, we recorded 1,183 individuals in 128 groups and one solitary adult male. As a result of government policies, poaching for food and traditional medicine is no longer a primary threat to these langurs. However, severe forest loss and fragmentation caused by human activities could limit any future increase of this langur population.

The amphibians of the Indonesian island of Sumatra are poorly known, despite it being recognized as a biodiversity hotspot. For determining conservation priorities, up-to-date knowledge of the state of amphibian diversity in Sumatra is crucial, particularly considering the high deforestation rate on the island. To address this, I compiled and analysed a comprehensive dataset for amphibians known from Sumatra, to identify knowledge gaps and assess the significance of these data for conservation on the island and, more broadly, across Indonesia. The compilation indicates there are 135 amphibian species currently recorded for Sumatra, 55% more than the number known in 1923. Approximately 44 species have been described since 2000. Associated data on larvae and calls is lacking for many species. Although 66% of the amphibians of Sumatra are categorized as Least Concern on the IUCN Red List, this may not represent the actual conservation status of these species because many of the assessments are outdated. In addition, 14% of species have not yet been evaluated. This study highlights the need for more comprehensive studies on the amphibians of Sumatra.

The gharial Gavialis gangeticus is a Critically Endangered crocodilian currently known from only 14 disjunct locations in Nepal and India. The protected stretch of the Babai River in Bardia National Park, Nepal, is home to one of the six subpopulations of gharials that have exhibited recent evidence of reproduction. However, there is limited information available on the gharial population in this region. We conducted surveys during the breeding, nesting and hatching seasons of gharials during 2020–2022 to study the gharial population in the Babai River in Bardia National Park. We located one breeding group of gharials in Soth Khola (2–3 individuals) and one in Dhanuse (5–6 individuals), and we observed pre-mating or mating behaviours in all 3 years. We identified potential nesting areas on sand banks of 19–175 m in length. During nesting seasons we found abundant signs of nesting only in Dhanuse, including entry and exit trails of female gharials to and from the water and trial nests. In 2020 and 2021 we did not find any signs of hatching, probably because of flooding. In 2022 we recorded two gharial nests, producing c. 60 hatchlings, in Dhanuse. Our findings indicate that the gharial population in the Babai River is probably nesting annually. We recommend various conservation actions for this gharial population.

Cave biodiversity and ecosystems are underexplored. To guide conservation needs for visitor management, we surveyed the 2,158 m long Danial Cave in northern Iran for vertebrate fauna. We identified four mammalian and two amphibian species in the cave: the greater horseshoe bat Rhinolophus ferrumequinum, Blasius's horseshoe bat Rhinolophus blasii, the lesser mouse-eared myotis Myotis blythii, the Hyrcanian field mouse Apodemus hyrcanicus, the Hyrcanian wood frog Rana pseudodalmatina and the Eurasian marsh frog Pelophylax ridibundus. Considering the increasing tourism pressures at Danial Cave, information on cave fauna is imperative for the conservation management of unique and endemic cave species.

The Javan tiger Panthera tigris sondaica and the Bali tiger P. tigris balica were categorized as Extinct on the IUCN Red List in both 2003 and 2008, leaving only the Sumatran subspecies P. tigris sumatrae extant in Indonesia. There have, however, been occasional, more recent reports of the Javan tiger but without conclusive evidence. Here, a potential observation in 2019 of a Javan tiger in a community plantation near the village of Cipendeuy in the forest of South Sukabumi, West Java, and a single hair found on a fence nearby, are assessed. The cytochrome b mitochondrial DNA (mtDNA) gene sequence of the putative Javan tiger hair were compared with that of a Javan tiger specimen in Museum Zoologicum Bogoriense, collected in 1930; hair samples of several tiger subspecies and the Javan leopard Panthera pardus melas were used as controls. The results showed that the genetic distances (d) of the putative Javan tiger hair with the Sumatran, Bengal P. tigris tigris and Amur P. tigris altaica tigers and the Javan leopard are 0.074 ± SE 0.009, 0.071 ± SE 0.009, 0.072 ± SE 0.009 and 0.088 ± SE 0.010, respectively, whereas the genetic distance of the putative Javan tiger hair with the Javan tiger museum specimen is 0.040 ± SE 0.006. In addition, phylogenetic trees showed that the putative Javan tiger hair sample belongs to the same group as the museum specimen of the Javan tiger, but is differentiated from other tiger subspecies and the Javan leopard. Whether the Javan tiger still occurs in the wild needs to be confirmed with further genetic and field studies.

Gibbons are often difficult to observe in dense forest habitats using traditional ground-based methods. This makes it challenging to estimate group sizes and, in turn, population sizes. This has proven to be a key constraint on accurate monitoring of the last remaining population of the Critically Endangered cao vit gibbon Nomascus nasutus. However, new technologies are beginning to circumvent the problems associated with traditional methods. We hypothesized that, by using an unoccupied aerial vehicle (UAV) equipped with thermal and standard (RGB) cameras, we could obtain more accurate group size counts than by using ground-based observations, as fewer gibbons would be missed. We tested this during a population survey of the cao vit gibbon, finding that the thermal video footage revealed additional individuals that were not counted by ground-based surveyors. Statistically, there was strong evidence (93% probability) that UAV-derived counts were higher (by 41%) than concurrent ground-based counts. We recorded six primate groups of three species (cao vit gibbon, rhesus macaque Macaca mulatta and Assamese macaque Macaca assamensis), including 24 gibbons across four groups (c. 20% of the global population). The RGB video footage also revealed seven female gibbons, two of which were carrying infants, providing vital group composition data. These data have contributed directly to a more accurate population survey of the species than would have been possible using direct observation only. We anticipate more widespread use of UAVs in the study of gibbons and other threatened species, leading to a more robust evidence base for their conservation.

Large carnivores such as the jaguar Panthera onca are particularly susceptible to population decline and local extinction as a result of habitat loss. Here we report on the long-term monitoring of a local jaguar population in a mixed land-use area in the eastern lowlands of Bolivia from March 2017 to December 2019. We recorded 15 jaguar individuals and four reproduction events (five offspring from three females), suggesting that our study area harbours a resident breeding population. Seven iterations of spatially explicit capture–recapture models provided density estimates of 1.32–3.57 jaguars per 100 km2. Jaguar capture rates were highest in forested areas, with few to no jaguar captures in pastures used for livestock. Massive deforestation after the survey period reduced the proportion of dense forest cover by 33%, shrinking the availability of suitable jaguar habitat and placing the resident jaguar population at risk. We use the jaguar as an indicator species to highlight the threat of habitat destruction in the Chiquitano region and we emphasize the importance of intact forest patches for jaguar conservation.

Protected areas worldwide are strongholds for safeguarding biodiversity, natural habitats, ecosystem services and cultural values. Yet despite their importance, the effectiveness of protected area management varies greatly. Indonesia is a biodiversity hotspot, with 554 protected areas that cover 27 million ha across the archipelago. To assess and improve the management effectiveness of these protected areas, the Government of Indonesia applied an adapted version of the Management Effectiveness Tracking Tool (METT) to assess 422 of the country's protected areas, of which 170 were repeatedly assessed in 2015, 2017 and 2019. We investigated the METT score changes across these protected areas and the factors explaining the varying scores. Over the study years, METT scores significantly improved (mean increase of 44.1%). National parks had the highest mean score, which was 13.4 points higher than other protected area types. After correcting for spatial autocorrelation using a generalized least-squares model, we found that METT score increase was positively influenced by year of assessment and having a well-resourced management authority, with no influence of protected area size or mean protected area budget allocation per ha. The assessments identified five main threats to protected areas: poaching, illegal logging, human settlements, tourism and non-timber cultivation. The widespread and repeated use of METT across the protected areas of Indonesia and the increasing METT scores indicate an overall improvement in management and professionalism. Building on the foundational work in our study, future studies should assess the association between METT scores and progress made towards achieving the conservation objectives of protected areas.

Interactions between people and the saltwater crocodile Crocodylus porosus frequently occur on islands and in coastal regions. Saltwater crocodiles impact people's lives and livelihoods by attacking them, resulting in minor or serious injuries, and by interfering in people's foraging activities. Retaliation may include killing the crocodiles involved. To reduce such human–crocodile interactions, data about the occurrence of incidents are required. We present data on encounters with crocodiles and attacks on people in the Roviana Lagoon, Solomon Islands. Data includes time of incident, gender, age and activity of the victim, water conditions and what happened to the crocodile after the incident. We used a questionnaire to capture the details of incidents that occurred during 2000–2020 in the villages of Dunde, Baraulu, Nusa Hope and Kozou. Most incidents were in the evening, mostly involving women, and most victims were aged 20–39 years or ≥ 60 years. In all cases people were attacked while gleaning for shellfish in the mangroves. Attacks occurred irrespective of whether the water was clear or murky, and in all cases the crocodiles were not killed. Such site-specific data will facilitate the formulation of strategies for reducing negative interactions between people and crocodiles in this particular location. Although the saltwater crocodile is categorized as Least Concern on the IUCN Red List, research such as this provides data that can be used for promoting coexistence with and conservation of this species.

The expansion of transportation and service corridors has numerous, well-documented adverse effects on wildlife. However, little research on this topic has been translated into mitigating the effects of habitat fragmentation caused by road development on primates. The establishment of canopy bridges has proven to be an effective conservation intervention. Of the completed primate canopy bridge projects reported in the literature, to our knowledge, all attempt to mitigate the impacts caused by singular, linear infrastructure routes. Here we provide recommendations for the establishment of a network of natural and artificial canopy bridges over roads throughout Langkawi Island, Malaysia, to reduce rates of roadkill and support the movement of primates and other arboreal animals across the island by identifying suitable sites and appropriate tree species to be planted (including Ficus racemosa and Ficus fistulosa), bridge materials and post-installation monitoring. The establishment of this pioneering trans-island canopy bridge network could function as a model to enhance connectivity for arboreal animals in other important wildlife habitat sites in Malaysia and beyond that are affected by fragmentation from linear infrastructure. We have begun discussions with relevant authorities, partners and other pertinent parties, focusing on the initiation of construction of the canopy bridge network in 2024.

Area-based conservation is a widely used approach for maintaining biodiversity, and there are ongoing discussions over what is an appropriate global conservation area coverage target. To inform such debates, it is necessary to know the extent and ecological representativeness of the current conservation area network, but this is hampered by gaps in existing global datasets. In particular, although data on privately and community-governed protected areas and other effective area-based conservation measures are often available at the national level, it can take many years to incorporate these into official datasets. This suggests a complementary approach is needed based on selecting a sample of countries and using their national-scale datasets to produce more accurate metrics. However, every country added to the sample increases the costs of data collection, collation and analysis. To address this, here we present a data collection framework underpinned by a spatial prioritization algorithm, which identifies a minimum set of countries that are also representative of 10 factors that influence conservation area establishment and biodiversity patterns. We then illustrate this approach by identifying a representative set of sampling units that cover 10% of the terrestrial realm, which included areas in only 25 countries. In contrast, selecting 10% of the terrestrial realm at random included areas across a mean of 162 countries. These sampling units could be the focus of future data collation on different types of conservation area. Analysing these data could produce more rapid and accurate estimates of global conservation area coverage and ecological representativeness, complementing existing international reporting systems.

The Endangered tiger Panthera tigris and Vulnerable snow leopard Panthera uncia are umbrella species and conservation priorities. Jigme Dorji National Park is an important protected area for the conservation of both species because it serves as a source site for tigers to adjacent areas and has the largest snow leopard population in Bhutan. Habitat overlap of tigers and snow leopards in Bhutan has been previously reported based on evidence of tigers (pugmarks, livestock killed and camera-trap images) in known snow leopard habitat above 4,000 m altitude. Here we report the first photographic evidence of both tigers and snow leopards at the same locations, confirming habitat overlap and co-occurrence of the two species. The data are derived from the countrywide tiger survey carried out during October 2021–January 2022. Fifty-six pairs of camera traps were installed in a 5 × 5 km grid at an altitude range of 1,200–4,300 m. After a survey effort of 1,528 trap-nights, 478 tiger images and 31 snow leopard images were captured at 12 and three camera stations, respectively. At all three camera stations that captured snow leopard images, tigers were also captured. These findings indicate the habitat overlap and co-occurrence of tigers and snow leopards in Jigme Dorji National Park. Further research is required to inform conservation practice in the National Park focusing on these apex predators.

Mammal populations are declining in biodiverse tropical regions. Global analyses have identified Indonesia as a hotspot of vertebrate decline, although relatively few data are available to substantiate these claims. We reviewed research articles published during 2000–2020 on 104 medium-sized to large terrestrial mammal species found in Indonesia to help inform conservation management and future research. We identified 308 peer-reviewed studies published in English or Bahasa Indonesia, with an increase in publication rate (articles published per year) over time. Studies of species distributions dominated the literature, followed by publications on abundance, species diversity and combinations of these topics. Most publications concerned single-species studies conducted at a single location and a single point in time. We identify four key issues that should be addressed by future research and conservation efforts: (1) disproportionate focus on a small number of species; (2) geographical bias towards west Indonesia (Sumatra, Kalimantan and Java–Bali), with few published studies from central (Sulawesi, Nusa Tenggara and Maluku) and east (Papua) Indonesia; (3) limitations to survey design, sampling effort and data analysis; and (4) lack of long-term wildlife population studies. We also note challenges local researchers face in publishing their studies in international journals because of language barriers and costs. Greater use of existing biodiversity data and continued capacity building for local researchers, particularly those in central and east Indonesia, are critical to effectively guide future wildlife monitoring and improve the conservation status of Indonesian mammals.

On the IUCN Red List the saltwater crocodile Crocodylus porosus is categorized globally as Least Concern, with national populations ranging from fully recovered to extinct. The saltwater crocodile population of the Southeast Asian island nation of Timor-Leste was severely depleted by colonial hunting but has recovered since independence in 2002. During 2007–2014 there was a 23-fold increase in reported crocodile attacks (104 documented attacks), concomitant with a 2% annual increase in the human population. Public tolerance to attacks and the reluctance to harm crocodiles are entwined with reverence of crocodiles as sacred beings by most but not all Timorese people. In 2022, 7–8 years after our previous assessment, we visited five sites on the south coast of Timor-Leste in Lautém, Viqueque, Manufahí and Cova Lima municipalities. High rates of crocodile attacks continue. We obtained 35 records of attacks for 2015–2022 (34% fatal). In the municipalities where crocodile attacks occurred (Lautém, Viqueque, Cova Lima), the sacred status of crocodiles prevented inhabitants from harming them in retribution. In Manufahí, where no attacks were reported, such traditional values never existed and crocodiles were hunted for subsistence and to improve safety. The design of a context-specific crocodile management programme that respects the reverence attributed to crocodiles by most people but reduces the risk of people being attacked by crocodiles is a conservation management challenge for the government of Timor-Leste. The developing tourism industry, which relies on coastal beaches and reefs, is jeopardized by the risk of crocodile attacks.

Surveys targeting flagship species frequently record the presence of other species, providing valuable bycatch data to fill knowledge gaps on the ecology of overlooked species. Using bycatch records from camera-trap surveys for the tiger Panthera tigris, we model occupancy of the sun bear Helarctos malayanus, predict its temporal change in occupancy during 2015–2019 and determine its activity patterns in Bukit Barisan Selatan National Park, part of a UNESCO World Heritage Site in Sumatra, Indonesia. We performed single-season occupancy modelling that considered unequal detection probability from sun bear detection/non-detection records. We found that the sun bear occupancy in the Intensive Protection Zone (i.e. the priority protection area) of the National Park was slightly higher than in the north of the National Park. In the Intensive Protection Zone, sun bear occupancy was estimated to be 0.67 in 2015 and increased to 0.83 in 2019, but this increase was not substantial. The sun bear exhibited a cathemeral activity pattern. Most activity occurred during the day (46.2%), followed by night (21.2%), dusk (20.9%) and dawn (11.7%). We encourage collaboration amongst institutions conducting camera-trap studies in Sumatra to examine the ecology of other threatened yet overlooked species, to assess the broader biodiversity benefits of flagship species conservation and to strengthen science-based conservation efforts.

The status of the forest elephant Loxodonta cyclotis in Guinea-Bissau has been in doubt since the last assessment in 2006. In 2020–2022 we carried out field surveys to update the species' status. We found elephant signs within an area of c. 1,000 km2. Microsatellite genotyping of faeces identified four males. Females could not be individually identified but their presence was confirmed by molecular sex determination. Camera trapping (2,075 camera-trap days) recorded 824 photos in 24 independent sequences, involving three males and two presumed females. The continued presence of elephants in Guinea-Bissau raises hope for the species in the region, but urgent efforts are needed to refine population range and size estimates, increase protected area coverage, and reduce ongoing and impending habitat loss. An emergency conservation action plan is a priority.

The Arabian leopard Panthera pardus nimr is categorized as Critically Endangered, with < 200 individuals estimated to remain in the wild. Historically the species ranged over an extensive area of western Saudi Arabia but, with no confirmed sightings since 2014, investigating potential continued presence and distribution is of critical conservation importance. We present the results of a comprehensive survey designed to detect any remaining Arabian leopard populations in Saudi Arabia. We conducted 14 surveys, deploying 586 camera-trap stations at 13 sites, totalling 82,075 trap-nights. Questionnaire surveys were conducted with 843 members of local communities across the Arabian leopard's historical range to assess the presence of leopards, other predators and prey species. Predator scats were collected ad hoc by field teams and we used mitochondrial DNA analysis to identify the originating species. We obtained 62,948 independent photographs of animals and people, but none were of Arabian leopards. Other carnivores appeared widespread and domestic animals were numerous, but wild prey were comparatively scarce. Three questionnaire respondents reported sightings of leopards within the previous year, but targeted camera-trap surveys in these areas did not yield evidence of leopards. Of the 143 scats sent for analysis, no DNA was conclusively identified as that of the leopard. From this extensive study, we conclude there are probably no surviving, sustainable populations of Arabian leopards in Saudi Arabia. Individual leopards might be present but were not confirmed. Any future Arabian leopard conservation in Saudi Arabia will probably require reintroduction of captive-bred leopards.

Protected areas are important for wildlife conservation but they are also used by many local communities for livelihood activities. This often leads to conflicts and erodes the tolerance of local people for wildlife, particularly towards carnivores that prey on livestock. To enhance conservation success and improve the social carrying capacity of carnivores, it is essential to understand the factors influencing such conflicts and the attitudes of people interacting with carnivores. We used structured questionnaire surveys to assess the extent of livestock mortality and community responses to common leopards Panthera pardus in Kishtwar National Park, a relatively understudied protected area in the Greater Himalayan region of India. The mountainous Park and its surroundings have historically served as a haven for the local agro-pastoralists and transhumant pastoralists, resulting in complex human–wildlife interactions across the larger landscape. Our results showed that leopards were responsible for high livestock depredation (71 incidents in 2 years), and households with larger livestock holdings experienced a higher predation rate compared to those with smaller livestock holdings. An ordinal logistic regression model revealed that respondents’ age and period of activity in the Park significantly influenced their opinions regarding leopards. Large losses suffered by otherwise low-income households resulted in more negative attitudes towards these predators. Our study indicates that financial compensation for livestock losses is a key factor in improving human–leopard coexistence. A comprehensive, cross-sector collaborative approach would help to improve conflict resolution and promote favourable attitudes towards these predators.