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Red List, this may not represent the actual conservation status of these species because many of the assessments are outdated.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 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.

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.

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.

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 plant species Sesbania tomentosa (‘ōhai; Fabaceae) is endemic to the Hawaiian Islands, federally listed as endangered in the USA and has been proposed for categorization as Vulnerable on the IUCN Red List. In 2021, c. 12,000 seeds from 12 seed lots collected during 1990–1992 from across the Hawaiian Islands were discovered in ambient herbarium conditions (55% relative humidity (RH) at 20 °C). International gene bank standards suggest drying seeds in equilibrium with 15% RH and stored at −18 °C. To investigate seed viability, we mechanically scarified then sowed 15 seeds from each accession at daily alternating regimes of 12 h light and 12 h dark at temperatures of 25/15 °C, respectively. Germination was observed after 7 days and ended after 34 days. Mean final germination was 88.9 ± SD 0.1% (range 73–100%). Each seed lot was accessioned into the National Tropical Botanical Garden's Seed Bank and Laboratory. In seeds with a water-impermeable seed coat (i.e. physical dormancy), such as S. tomentosa, seeds can desorb but not absorb water. Therefore, if the seeds were initially dried, although exposed to high RH for up to 32 years, seed equilibrium RH may have remained low, which may in part explain the observed high germinability. This study holds significance for managers who are working to conserve this endangered Hawaiian species and suggests that even suboptimal conditions may still yield highly viable seeds several decades into the future.

Predation can have cascading, regulatory effects across ecological communities. Knowledge of the diet of predators can therefore provide important information regarding their ecology and conservation, as well as their impacts on prey populations. Using scats collected during 2019–2023 and estimates of prey abundance from aerial surveys, we characterized prey consumption and preferences of the Vulnerable African lion Panthera leo population in Tsavo, Kenya. Biomass models applied to prey frequencies in scats revealed that > 85% of lion diet comprised large ungulates weighing > 150 kg. The Critically Endangered hirola Beatragus hunteri and Endangered Grevy's zebra Equus grevyi (species that were introduced in Tsavo as part of ex situ conservation programmes in the 1960s) were amongst the seven prey species, of 16 detected, that were preferred by lions. Our results potentially indicate a disproportionate impact of lion predation on the small hirola and Grevy's zebra populations. Preferential predation, coupled with high availability of alternative prey, may trap the small populations of hirola and Grevy's zebra within a predator pit. Our findings provide a better understanding of lion diet, optimal foraging and the potential effects predators can have on threatened and rare prey species in an important conservation landscape. Based on our findings, we recommend an observational study of the predation ecology of lions and other predators in this system, to provide information on age- and sex-specific predation rates on hirola and Grevy's zebra for a population viability analysis, to support the management of these two threatened and rare herbivores in Tsavo.

Conservation monitoring is paramount for the gathering of information on species and populations in need of conservation actions. However, monitoring of the mountain bongo Tragelaphus eurycerus isaaci, a Critically Endangered antelope endemic to Kenya, has hitherto been limited to surveillance (i.e. focused on persistence of the species in particular areas), thus limiting the information that could be retrieved on the status and trends of these populations. Using a newly developed identification system, we implemented robust design mark–recapture using existing camera-trap records of four wild subpopulations of the bongo. We provide data on sex and age structure and the first estimates of population size in the wild. Males and calves seem to be suffering higher mortality than females, and only two of the four monitored populations include adults of both sexes and calves. The combined size of these two breeding populations is estimated to be 29–50. Our findings confirm the critical situation of the mountain bongo in the wild and highlight the need for conservation actions to reinforce the wild populations for the long-term conservation of this antelope.

Biodiversity monitoring programmes should be designed with sufficient statistical power to detect population change. Here we evaluated the statistical power of monitoring to detect declines in the occupancy of forest birds on Christmas Island, Australia. We fitted zero-inflated binomial models to 3 years of repeat detection data (2011, 2013 and 2015) to estimate single-visit detection probabilities for four species of concern: the Christmas Island imperial pigeon Ducula whartoni, Christmas Island white-eye Zosterops natalis, Christmas Island thrush Turdus poliocephalus erythropleurus and Christmas Island emerald dove Chalcophaps indica natalis. We combined detection probabilities with maps of occupancy to simulate data collected over the next 10 years for alternative monitoring designs and for different declines in occupancy (10–50%). Specifically, we explored how the number of sites (60, 128, 300, 500), the interval between surveys (1–5 years), the number of repeat visits (2–4 visits) and the location of sites influenced power. Power was high (> 80%) for the imperial pigeon, white-eye and thrush for most scenarios, except for when only 60 sites were surveyed or a 10% decline in occupancy was simulated over 10 years. For the emerald dove, which is the rarest of the four species and has a patchy distribution, power was low in almost all scenarios tested. Prioritizing monitoring towards core habitat for this species only slightly improved power to detect declines. Our study demonstrates how data collected during the early stages of monitoring can be analysed in simulation tools to fine-tune future survey design decisions.

The cheetah Acinonyx jubatus has suffered considerable range contractions in recent decades. Despite the importance of up-to-date information on distribution to guide conservation, such information is lacking for large areas within the species’ remaining potential range. In Tanzania, the largest tract of potential cheetah habitat without such data is the Selous–Nyerere ecosystem. Although the cheetah is considered possibly extant in this landscape, the last confirmed sighting was in the late 1990s. During 2020–2022, we carried out sign-based (spoor) and camera-trap surveys across Selous Game Reserve and Nyerere National Park. We did not record any evidence of cheetah presence, and opportunistic enquiries with tourism operators and protected area management staff did not provide any evidence of current or recent presence. Our findings suggest that current cheetah presence is unlikely, and that Selous–Nyerere should not be treated as potential contemporary cheetah range. We discuss the possibility that Selous–Nyerere may have never hosted a resident cheetah population, and was either occasionally occupied by dispersers from other populations or represented the edge of populations that spanned areas now treated as corridors.

The Fingui white-toothed shrew Crocidura fingui, categorized as Data Deficient on the IUCN Red List, is endemic to Príncipe Island, Central Africa. It is currently known from < 10 sites and its ecology and any threats are largely unknown. We review its distribution and ecology, and any potential threats, based on camera-trap data, field observations and previously published and unpublished sightings. Crocidura fingui appears to have an island-wide distribution and to use a range of ecosystems, from native forests to urban areas. It is largely nocturnal and exhibits considerable spatiotemporal overlap with introduced mammals such as the African civet Civettictis civetta, domestic cat Felis catus and rats Rattus spp. The species has an area of occupancy < 500 km2 and is known from fewer than five locations, and its population is inferred to be affected by several introduced mammals. We recommend that it is recategorized as Endangered on the IUCN Red List.