The little-known Bristled Grassbird Chaetornis striata is thought to be declining due to the loss of grassland habitats throughout its range, and is currently classified as globally ‘Vulnerable’. In order to investigate the current status and possible causes of the presumed decline, we assessed population density of Bristled Grassbird in Padma and Jamuna river systems of Bangladesh. The study was conducted during the breeding seasons of the Bristled Grassbird in April and May in 2016–2019, using distance sampling and habitat suitability modelling. We also examined habitat preferences and responses to environmental changes based on vegetation structure and habitat modifications at point count locations. We detected a total of 39 birds with a mean group size of 1.44 individuals. We estimated 4.52 (95% CI: 2.65–7.73) individuals per km2 with an encounter rate of 1.48 detections per point count station and 341.15 birds within the study area. Our habitat suitability model projected a total of 167.41 km2 of suitable habitat and a total of 756.7 birds in floodplain grasslands of Padma and Jamuna river systems. The Bristled Grassbird was positively associated with grass height and grass density with 92.31% of 39 detections at Saccharum spontaneum dominated grasslands. We did not find a significant effect on Bristled Grassbird detections with increasing human activities, although the detection rate decreased linearly with increasing agricultural intervention and grass harvesting. These findings indicate that the Bristled Grassbird is more widely distributed throughout Bangladesh, and may be less vulnerable to grassland modifications, than previously thought.

The hog deer Axis porcinus formerly occurred in south-west China but has not been recorded there since 1965. To investigate the current status of the species in China, we conducted interviews, and transect and camera-trap surveys during October 2018–June 2020 to search for signs of hog deer across its historical range in the country. We interviewed 50 local inhabitants and surveyed 14 line transects in four counties of Lincang City, Yunnan Province. The camera traps were deployed in Nangunhe Nature Reserve (39.4 km of transects, 82 camera stations, 15,120 camera days) and Daxueshan Nature Reserve (41.1 km of transects, 68 camera stations, 13,554 camera days). We found no hog deer tracks and no hog deer were trapped by cameras. The floodplain grasslands preferred by hog deer along Nanting River have been transformed into agriculture plantations and human settlements. Our findings suggest that hog deer may have been extirpated from China, most likely as a result of habitat loss and overhunting. The conservation priorities for this species in China are the establishment of a protected area in the Nanting River watershed, restoration of habitat and reintroduction of individuals from range countries.

The Giant Nuthatch Sitta magna is a globally endangered species presumed to be declining, for which basic parameters of population and habitat associations remain largely unquantified. We focused on Myanmar, which potentially constitutes ~30% of the Giant Nuthatch global range and yet lacks recently published records. Our objectives were to survey key potential Giant Nuthatch localities in, or near, historical locations in Southern Shan State, assess its population status, and quantify habitat associations. Preliminary locality surveys focused on four potential forest patches, assessed by walking approximately 40 km of trails. The species was found in only one of the four localities (Mt. Ashae Myin Anauk Myin [AMAM]), an 18 km2 forest patch in Pindaya and Lawksawk Townships. Here, point counts and vegetation surveys were conducted at 46 locations using an adaptive cluster sampling design. N-mixture models were applied to estimate abundance and identify habitat variables correlated with abundance and detection probability. We also conducted a brief quantitative assessment of tree use and foraging behaviour during one breeding season. Our population estimate for AMAM was 56 individuals (95% CI 25–128) based on a sampled area of 3.25 km2. Abundance was positively associated with larger diameter trees, a higher proportion of pine and oak combined based on their total basal area, and negatively correlated with elevation. Foraging data suggested that Giant Nuthatch preferred to feed on trunks and large branches of larger diameter pines and Fagaceae trees. Based on the estimated population size, AMAM is probably a globally significant locality for Giant Nuthatch and the only confirmed locality in Myanmar since 1992 but is threatened by agricultural expansion. More detailed understanding of the habitat requirements of this endangered species and an assessment of its distribution at the landscape-level, especially in Shan State, would increase the precision of global population estimates.

The rare and threatened fern Christensenia aesculifolia of South-east Asia is listed in China as a second-ranked plant for national protection and is also categorized as one of 62 plant species with extremely small populations by the Yunnan provincial government. Field investigations during 2014–2017 failed to relocate one previously known population, and revealed that the single known extant population of C. aesculifolia contains only 10 individual plants. The most urgent conservation requirement for this species is to conserve the threatened habitat of the remnant population. Further field surveys and research are also required for an improved understanding of the species’ status.

Available information about seabird breeding population trends on Stinker Point (Elephant Island, Maritime Antarctic Peninsula) is outdated by decades. This study reports current numbers of breeding species, and evaluates population trends over 28 years. We counted breeding pairs of seabirds along all ice-free areas on Stinker Point during two distinct periods (summers of 1985/86–1991/92 and 2009/10–2013/14). Thirteen species currently breed in the area: four Sphenisciformes, four Procellariiformes, one Suliforme and four Charadriiformes. Chinstrap penguin Pygoscelis antarcticus has the highest number of breeding pairs (4971±590), followed by gentoo penguin Pygoscelis papua (1242±339). Comparisons between the two intervals showed declining trends for almost all breeding populations, although southern giant petrels Macronectes giganteus are experiencing a subtle population growth. Population decreases in locations with low human disturbance, such as Stinker Point, may indicate sensibility to climate and environmental change and need further investigation.

The conservation status of threatened taxa may be obfuscated by the detection of cryptic species complexes, in both vertebrate and invertebrate species. African dwarf crocodiles (Osteolaemus spp.) are hunted throughout their range but their conservation status is unknown. Few population assessments have been carried out and there has been a taxonomic revision of the number of species in the genus. The similar morphologies of Osteolaemus tetraspis and Osteolaemus osborni pose a challenge for conservation in Cameroon, where they are still managed as a single species. Nocturnal spotlight surveys were conducted in three regions during August–November 2010 and December 2011–February 2012 to provide population assessments of O. tetraspis and O. osborni and raise awareness of the two species in Cameroon. The mean encounter rates of O. tetraspis and O. osborni were 1.02 ± SD 1.34 (65 individuals in 39 surveys) and 0.61 ± SD 0.38 (three in four surveys) crocodiles per km, respectively. The O. tetraspis population comprised juveniles predominantly and had a male-biased sex ratio. The few O. osborni detected comprised both adults and juveniles. Both species are threatened in Cameroon, based on low encounter rates, young population structures and the threats of habitat loss and hunting pressure. This study provides distribution maps and serves as a baseline to quantify population trends and inform conservation strategies.

As peat-swamp forests in Borneo become progressively more fragmented, the species that inhabit them are increasingly threatened, notably the Endangered Bornean orang-utan Pongo pygmaeus. The area of a failed agricultural project known as the Mega Rice Project in Central Kalimantan, Indonesia, is composed of fragments of peat-swamp forest that are reported to contain orang-utans, although no comprehensive survey has previously been conducted. In a portion of this area we identified remaining forest fragments, using satellite imagery, and surveyed line transects for orang-utan sleeping nests to determine the density, abundance and distribution of the species. The total area of peat-swamp forest in the study area is 76,755 ha, 59,948 ha of which comprises patches at least as large as the home range of a female orang-utan (250 ha). We estimate a mean population density of 2.48 ± SE 0.32 individuals km−2 and a population of 1,700 ± SE 220 or 1,507 ± SE 195 individuals, based on a 25 and 250 ha minimum patch size threshold, respectively. This is c. 40–45% of the original population, and the fragmented population is unlikely to be viable in terms of long-term demographic and genetic stability. To ensure persistence of this population of orang-utans, direct conservation action to connect forest fragments and prevent further loss of peat-swamp forest will be required, including re-establishing the hydrological regime, reforesting barren areas and fighting fires.

The current status and distribution of the Vulnerable Reeves's pheasant Syrmaticus reevesii, endemic to central China, is poorly known. To obtain updated information on its status we selected 89 candidate sites in six provinces and one municipality in central China and conducted interviews and field surveys from April 2011 to April 2012. Interviews demonstrated the pheasant has disappeared from 46% of the surveyed sites. Our results also revealed a population decline at 46 sites, including protected areas, although population densities in protected areas were higher than those in non-protected areas. Eighty-three, 26 and 20% of the surveyed sites had evidence of poaching, habitat loss and use of poison, respectively, which were the three major threats to this species. To ensure the long-term survival of Reeves's pheasant in China, protection and management need to be enforced in both protected and non-protected areas. We recommend that this species should be upgraded to a national first-level protected species in China and recategorized as Endangered on the IUCN Red List.

We report a range-wide status assessment of a key Neotropical ecosystem architect, the white-lipped peccary Tayassu pecari, categorized as Near Threatened on the IUCN Red List, using published information and unpublished data from 41 scientists in 15 range countries. We estimate that the white-lipped peccary has been extirpated in 21% of its historical range over the last 100 years, with reduced abundance and a low to medium probability of long-term survival in another 48% of its current range. We found major range declines in Argentina, Paraguay, southern Brazil, Colombia, Venezuela, north-east Brazil, Mexico and Costa Rica. This species is particularly at risk in more xeric ecosystems, especially the caatinga, cerrado and pampas. Hunting and habitat destruction are the most severe threats, although there are also unexplained sudden die-offs suggestive of disease. We evaluate our results in light of this species’ important interspecific interactions and its role as an ecosystem architect. One of our recommendations is that conservation efforts should focus on landscape conservation of large, continuous and ecologically intact areas containing a mosaic of different habitat types.

The Chelonia face an extinction crisis, particularly in Asia: unsustainable harvests, and habitat fragmentation and loss accompanying rapid urbanization and land development all pose threats to turtles. These threats are particularly acute for those species with a high commercial value such as the yellow-margined box turtle Cuora flavomarginata. Because of burgeoning demand in the food and pet markets, combined with extensive habitat loss, C. flavomarginata is categorized as Endangered on the IUCN Red List. To investigate the status and distribution of this species in Taiwan we conducted an extensive trapping survey in 2001–2008, locating a total of 527 different individuals at 23 sites. Our results show that C. flavomarginata is restricted to low-elevation forested hills. Populations in lowland areas may have been extirpated by land development. There are four clusters of localities in low-elevation primary and secondary forests, and some relatively large populations survive. However, capture success at most sites was low. In those sites where we trapped > 20 individuals, sex ratios were significantly skewed towards females and adults predominated. The most essential measure for the conservation of C. flavomarginata in Taiwan is to secure and preserve some relatively undisturbed habitats at low elevations.

The Egyptian vulture Neophron percnopterus is categorized as Endangered on the IUCN Red List, as well as on the European and Spanish Red Lists. Spain is home to the most important breeding population of Egyptian vultures in Europe but this population has differing trends at a regional scale. We present data for the Egyptian vulture population in the Cantabrian Mountains, north-west Spain, during the last 3 decades and assess the main threats to the species there. The Egyptian vulture population in the Cantabrian Mountains was estimated to be 175 breeding pairs in 2008, which comprised 13–14% of the Spanish population. This population has been stable, or increasing slightly, since 2000. During 2000–2008 4.3% of the Cantabrian Egyptian vulture population was affected by the use of illegal poison. During the same period the number of sheep and goats reared (which contributes to the maintenance of Egyptian vulture territories) was reduced by 27.4%, which could lead to food shortages for the vultures in the near future. Currently 32 breeding pairs (18.3% of the population) have wind turbines within their foraging areas, with an average of 59 wind turbines per territory (range 1–176). During the next few years this number will increase to 110 turbines per territory within 69 vulture territories (39.4% of the population). Nearly a third (32.6%) of breeding territories are located outside protected areas. Better coordination between administrative areas is needed to guarantee the conservation of the Cantabrian Mountains population of Egyptian vultures through effective surveillance and protection in the numerous existing protected areas.

The Ross seal (Ommatophoca rossii) is the least studied of the Antarctic ice-breeding phocids. In particular, estimating the population status of the Ross seal has proved extremely difficult. The Protocol on Environmental Protection to the Antarctic Treaty currently designates the Ross seal as a ‘Specially Protected Species’, contrasting with the IUCN's classification of ‘Least Concern’. As part of a review of the Ross seal's classification under the Protocol, a survey was undertaken in 1999/2000 to estimate the status of the Ross seal population in the pack ice off East Antarctica between 64–150°E. Shipboard and aerial sighting surveys were carried out along 9476 km of transect to estimate the density of Ross seals hauled out on the ice, and satellite dive recorders deployed on a sample of Ross seals to estimate the proportion of time spent on the ice. The survey design and analysis addressed the many sources of uncertainty in estimating the abundance of this species in an effort to provide a range of best and plausible estimates. Best estimates of abundance in the survey region ranged from 41 300–55 900 seals. Limits on plausible estimates ranged from 20 500 (lower 2.5 percentile) to 226 600 (upper 97.5 percentile).

The Tucumán parrot Amazona tucumana is a rare, Near Threatened species on CITES Appendix I with a restricted range in the tropical and subtropical montane forests of Argentina and Bolivia. We assessed the conservation status of the species in Argentina based on a detailed review of available information and an extensive survey throughout its range. A total of 6,015 individuals were detected in 14 sites, eight of which are new localities. The total number recorded in this study represents less than a third of the number exported from Argentina between 1985 and 1989 (18,641), indicating a significant reduction in population size. Research needs to be extended to additional sites, especially in Bolivia, to assess further the global status of the species, and high priority given to the creation of state and private reserves for the species.

The narrow-striped mongoose Mungotictis decemlineata is a small, endemic carnivore currently known to occur only in the dry deciduous forests of the central and southern Menabe regions of western Madagascar. It is categorized as Endangered on the IUCN Red List and is threatened by rapid habitat loss from deforestation. From live-trapping and village surveys we found M. decemlineata to be distributed throughout the largest area of connected forest in central Menabe and most of the larger forest fragments in southern Menabe. We estimated there are a minimum of 2,000–3,400 adults in central Menabe and 6,400–8,650 adults in southern Menabe. Although this represents the total known population, the southern limits of the species' range are still unclear. Fifty-four individuals were live-trapped in central Menabe. M. decemlineata abundance was not correlated with forest structure or invertebrate abundance and diversity at the sampled sites. The building of access roads for logging may have a long-lasting effect by increasing the level of human disturbance, predation by domestic dogs, and illegal cutting within the surrounding area. Conservation management efforts to save M. decemlineata need immediate implementation, with emphasis on cooperative efforts with local villages to reduce the rate of slash-and-burn agriculture and logging of the remaining dry deciduous forest of the region. Research to determine population trends and status of M. decemlineata south of the Morondava and Mangoky rivers is required.

The Mauritius olive white-eye Zosterops chloronothos is the least known of the eight threatened terrestrial bird species remaining on the island of Mauritius. The olive white-eye has declined drastically in numbers and distribution since 1975. Surveys carried out between 1998 and 2001 estimated that 93–148 pairs remained within an area of less than 25 km2. Most areas that held olive white-eye territories in 1975 supported considerably fewer territories in 2001. This decline is thought to have primarily been the result of deforestation and degradation of native habitat and intense nest predation by introduced mammals. Declines have been more severe in areas dominated by native vegetation than they have been in areas that contained substantial amounts of exotic Cryptomeria and Pinus. The continued decline of the Mauritius olive white-eye is of critical concern and immediate species-specific conservation management is required for its survival.

A new breeding site of the globally threatened Chinese egret Egretta eulophotes was recorded on Furugelm Island in the summer of 1998. The discovery of this colony moves the breeding limit of the species more than 600 km further to the north-east in the Sea of Japan. Thirty to forty pairs of Chinese egrets were discovered on the island, which is also home to thousands of colonial seabirds as well. The egret's colony is within the Far-Eastern Marine Reserve but some of its main foraging sites lie outside the protected area and are disturbed by both tourists and hunters. More worryingly, however, the main threat to the Chinese egret's survival is a new economic development project: the Tumen River Area Development Program. We make an urgent plea for the protection of the Chinese egrets' foraging areas within the Far-Eastern Marine Reserve and recommend that a transfrontier reserve be created to enhance the protection of this important waterbird site.