Estimating the population size of shy and elusive species is challenging but necessary to inform appropriate conservation actions for threatened or declining species. Using camera-trap surveys conducted during 2017–2021, we estimated and compared African clawless otter Aonyx capensis population densities and activity times in six conserved areas in southern Africa. We used two different models to estimate densities: random encounter models and camera-trap distance sampling. Our results highlight a general pattern of higher estimated densities and narrower confidence intervals using random encounter models compared to camera-trap distance sampling. We found substantial variation in densities between study areas, with random encounter model estimates ranging between 0.9 and 4.2 otters/km2. Our camera-trap distance sampling estimates supported the relative density estimates obtained from random encounter models but were generally lower and more variable, ranging from 0.8 to 4.0 otters/km2. We found significant differences in otter activity patterns, with populations either being nocturnal, mostly nocturnal or cathemeral. As all study areas experience little human disturbance, our results suggest that there are large natural variations in otter densities and activity patterns between regions. When densities are converted to metrics that are comparable to previous studies, our estimates suggest that African clawless otter population numbers are generally lower than previously reported. This highlights a need for broader spatial coverage of otter population assessments and future studies to assess potential environmental drivers of spatial, and potentially temporal, variation in population numbers and activity patterns.

Conservation management in human-modified landscapes requires information on the sustainability of interactions between people and biodiversity. Wild Chinese alligators Alligator sinensis only persist within the National Chinese Alligator Reserve in south-eastern China, where they live alongside agricultural communities that utilize local terrestrial and wetland habitats. We conducted an interview survey of communities within and around the Reserve to evaluate whether local ecological knowledge can provide a baseline on the species' local status and trends, and to understand the relationships between land-use practices and alligator presence and survival. Respondents within the Reserve were more likely to recognize alligators, report sightings and perceive declines than other respondents. Absolute levels of knowledge and experience of alligators were low, highlighting the species' perilous status, and analysis of correlative patterns between respondents' experiences and associated data on human–environmental interactions provides new conservation-relevant insights. Alligator sightings were more likely to be reported by respondents who did not grow crops, and eggs and nests by those who did not utilize local water sources for irrigation, suggesting that existing environmental pressures associated with agriculture may be unsustainable for alligators. Although respondents who lived outside the Reserve were more likely to use agrochemicals, we found no relationship between pesticide or fertilizer usage and variation in respondent awareness or experience of alligators. Our findings indicate that China's last wild alligators continue to experience negative human pressures, and current land-use practices are probably incompatible with long-term alligator survival.

Camera traps are widely used to study wildlife. However, theft and vandalism are frequent, resulting in millions of dollars in financial losses and large data gaps in research. Here we report on the impacts of camera-trap theft on a study examining wildlife movement under highway bridges in south-west Costa Rica. Even with metal cases, locks and signs installed on all camera traps, 65% were stolen. The working camera traps accumulated a total of 167 trap-nights and detected only two wild mammal species, eight bird species and one reptile species, as well as three domestic animal species and people. This limited number of wild species was unexpected given the known presence of wide-ranging megafauna and a diverse terrestrial mammal community in the region. The pervasive theft of camera traps leads to data gaps and impairs the potential for research in the region, and we discuss the potential additional reasons for detecting only a small number of species. Our findings highlight the need for solutions to camera-trap theft, to limit financial and data losses for conservation.

E-commerce applications have significantly changed how people transact with each other. This includes digital advances that drive illegal wildlife trade. In Indonesia, the Conservation Act of 1990 was enacted before the internet revolution and does not, therefore, adequately cover online illegal wildlife trade. In this study we identified wildlife traded illegally through advertisements published by five large national e-commerce companies and one social media platform operating in Indonesia, using 39 keywords. We also analysed data on wildlife cybercrime court case outcomes, associated criminal networks and their modus operandi. Over 12 months, we found 996 advertisements for wildlife and wildlife products, including of 45 nationally protected species, from 421 accounts. Amongst the six platforms monitored, Facebook Marketplace had the highest illegal wildlife trade traffic. We found that those prosecuted for online illegal wildlife trade were given low sentences. Our analysis of wildlife legislation, focus group discussions and expert interviews showed that the Government of Indonesia Trade Law (2014) and Law on Electronic Information and Transactions (2008) cannot be used to prosecute online illegal wildlife trade cases because these laws do not acknowledge regulations for protected species. Our study emphasizes the urgency of revising the Conservation Act and changing the definition of trade to include advertisements of protected species. We recommend development of screening tools for advertisements and accounts on e-commerce platforms, review of community/user guidelines to prohibit trade of protected species, and strengthening the approach of combining multi-context laws with stakeholder cooperation to prosecute online illegal wildlife trade cases.

The pelagic thresher shark Alopias pelagicus is an Evolutionarily Distinct and Globally Endangered species primarily threatened by overfishing. Indonesia is the world's largest shark fishing nation, and in Alor Island, thresher sharks have been a primary target for small-scale fishing communities for decades, sustaining subsistence livelihoods and serving as a protein source. With thresher shark populations continuously declining, there is a need for conservation measures to reduce shark mortality from fishing, while also securing the well-being of coastal communities. This study presents results and lessons learnt from a multi-faceted effort to reduce communities’ dependence on this Endangered shark species through a livelihood-based intervention complemented by collaborative species management and community outreach. Using a theory-based and statistical research design, we describe the approach taken in our intervention and its conservation outcomes. Total thresher shark catches were 91% lower among fishers who participated in our intervention compared to non-participants. Participating fishers also experienced increases in their income, in some cases by up to 525% relative to the income before the intervention. Occasional violations and challenges in the form of socio-political conflicts also occurred, yet these incidents acted as catalysts for regulatory change and reinforced stakeholder collaboration. This suggests overall positive outcomes and the potential for continued social change in shark conservation in the region over the long term. Our findings outline some generalizable lessons learnt for designing and implementing bottom-up livelihood-based interventions in other contexts.

Illegal hunting of migratory birds across the Mediterranean region is a serious international conservation issue with population-level impacts. We analysed photographs posted on social media platforms to assess the bird species illegally targeted in Lebanon. During 2011–2023 we reviewed 1,844 photographs publicly posted by poachers on Facebook and Instagram. In these images we identified 212 bird species, of which 94% are legally protected. Many are species of conservation concern, with 19 listed as threatened or Near Threatened on the IUCN Red List and 33% experiencing population declines in Europe. The five bird species with the most individuals illegally killed were the barn swallow Hirundo rustica, blackcap Sylvia atricapilla, European bee-eater Merops apiaster, Eurasian golden oriole Oriolus oriolus and ortolan bunting Emberiza hortulana. Raptors and other large soaring birds were particularly prevalent, with 35 species of raptor (particularly the European honey-buzzard Pernis apivorus, Eurasian sparrowhawk Accipiter nisus, common kestrel Falco tinnunculus, short-toed snake-eagle Circaetus gallicus and Levant sparrowhawk Accipiter brevipes) as well as storks, pelicans and cranes. Protected mammals were also posted as trophies, including the Near Threatened striped hyaena Hyaena hyaena. Poachers were present in 44% of photographs and were clearly identifiable 89% of the time, showing little concern about posting illegal activities on publicly accessible social media platforms. Our study is the first to use social media as a tool for assessing illegal hunting activities in Lebanon. We discuss both the use and limitations of this approach, as well as the ways in which social media can be utilized by law enforcement, to promote legal hunting or hunting alternatives and improve conservation education.

The Critically Endangered Arabian leopard Panthera pardus nimr was believed to be absent from the Nejd region in Dhofar Governorate, Oman. However, a scat confirmed by DNA analysis in 2011 and camera-trap images from 2014 confirmed the presence of the leopard in this region. During 2014–2021, our camera traps documented at least eight individual leopards, demonstrating the species is resident and breeding in the region. This finding extends the Arabian leopard's known range in Oman by c. 40 km northwards. To improve detection probability, we recommend that camera-trap surveys for the leopard in the Arabian Peninsula are of at least 18 weeks duration. We advocate the designation of central and western areas of the Nejd as a National Nature Reserve, to protect critical habitat for the Arabian leopard and for other species in this region.

Conservation aquaculture, defined as cultivating aquatic organisms to manage or replenish natural populations, has been advocated as a strategy to enhance fisheries production and help restore declining populations. Culture is especially compelling for species in steep decline and for which there is established methodology. The queen conch Aliger gigas is an example of a species with widely overexploited populations, with attempts to culture the species commercially ongoing for > 40 years. However, hatchery-releases have shown low survival from post-settlement to near maturity, leading to low conservation aquaculture potential. When this is viewed alongside large-scale fishery extractions, it is apparent that it is not commercially feasible to replace wild harvest nor ecologically feasible to replenish queen conch populations using existing aquaculture approaches. An age-based mortality model estimates the magnitude of culture required to replace a single adult of reproductive age. Extrapolations from catch–weight relationships highlight the scale of facilities and costs required to partially offset the harvest in a typical Caribbean fishery. Estimates of reproduction to achieve replacement suggest a greater yield from properly protecting natural breeding aggregations. Queen conch aquaculture is useful for scientific inquiry, community engagement and education, but not for stock enhancement or population restoration without more practical and cost-efficient options. Therefore, protecting breeding aggregations should be prioritized for the ecological viability of the species, as well as for its economic value for the people and industries that rely upon it.

The spotted hyaena Crocuta crocuta is relatively understudied across its range despite evidence of widespread declines. It is therefore essential that robust baseline population density assessments are conducted to inform current management and future conservation policy. In Mozambique this is urgent as decades of armed conflict followed by unchecked poaching have resulted in large-scale wildlife declines and extirpations. We conducted the first robust population density estimate for a spotted hyaena population in Mozambique using spatially explicit capture–recapture methodologies. We recorded a relatively low population density of 0.8–2.1 hyaenas/100 km2 in the wildlife management area Coutada 11 in the Zambezi Delta of central Mozambique in 2021. These densities are well below the estimated carrying capacity for the landscape and are comparable to published densities in high human-impact, miombo woodland-dominated and arid environments. The combination of historical armed conflict, marginal trophy hunting and bushmeat poaching using wire snares and gin traps (with physical injuries evident in 9% of identified individuals) presents persistent anthropogenic pressure, limiting the post-war recovery of this resident hyaena population. We provide insights into the dynamics of hyaena population status and recovery in such post-war landscapes, adding to mounting evidence that the species is less resilient to severe anthropogenic disturbances than previously believed. We recommend long-term monitoring of this and other carnivore populations in post-war landscapes to ascertain demographic trends and implement effective conservation interventions for population recovery.

The export of ornamental fishes from Malawi has received limited attention regarding its sustainability or the conservation status of any threatened species involved in this trade. To identify any species that require specific management actions, we used a negative binomial regression model to examine the relationship between the number of exported fish and year of export, adjusted for fish prices and the number of fish exporters. We also examined the correlation between export volume trends and the conservation status of fish species. We identified three groups of fish species based on their export volume trends: species with no trends, with decreasing trends and with increasing trends. There was no significant correlation between export volume trends and the conservation status of fish species. The export volume trends of individual species appear to be related to the number of exporters, price and, potentially, anthropogenic factors affecting fish populations. Based on our findings we recommend the inclusion of ornamental fishery management issues in a revised Fisheries and Aquaculture Policy. This should include strategies to control overexploitation of species with declining export volume trends, and conservation of threatened species and a ban on their export. We recommend further research to establish the population status of the exploited fish species and to identify any other factors linked to the volume trends of ornamental fish exports.

Mouse lemurs Microcebus spp. are small, nocturnal primates endemic to Madagascar. The genus is extraordinarily diverse, with 25 extant species, several of which have been described recently. The Endangered Claire's mouse lemur Microcebus mamiratra was first described in 2006, but, similarly to other newly described mouse lemurs, remains understudied, and estimates of its population size are unavailable, hampering effective conservation management. We conducted line transect distance sampling surveys of M. mamiratra across several habitat types in and around Lokobe National Park on the island of Nosy Be in north-western Madagascar. Using a systematic random design we surveyed 15 transects over a 6-week period in 2023, recording 92 detections from a total survey effort of 46.5 km. We estimate the density of M. mamiratra on Nosy Be to be 125.1 individuals/km2, which extrapolates to an estimate of c. 4,700 individuals across the forested areas of its range on the island. Our results indicate that Nosy Be harbours moderately high densities of M. mamiratra, with the highest encounter rates in the unprotected secondary and degraded forests around Lokobe National Park. Our population estimate will inform future conservation status assessments and conservation planning for this range-restricted species and provide a baseline for monitoring population changes over time. We present recommendations for the conservation of M. mamiratra and highlight the potential for lemur watching, sustained by the strong tourism industry on Nosy Be, to help protect lemur habitat and generate economic opportunities for local communities.

Climate and land-use changes are major threats to amphibian conservation. However, amphibians on tropical oceanic islands appear to have been overlooked with regards to their vulnerability to global anthropogenic threats. Here we examine whether there are gaps in research evaluating the vulnerability of tropical oceanic island amphibians to climate and land-use changes. We carried out a systematic review of the literature on experimental studies published during 1 July 1998–30 June 2022, to evaluate whether there are knowledge gaps in relation to geographical scope, taxonomic representation, life stage assessment, the factors affecting amphibians and how species and populations respond to these factors. Of 327 articles on climate change and 451 on land-use change, the research of only 18 was carried out on tropical oceanic islands, only on anurans, and < 20% of the authors were affiliated with an oceanic island institution. These 18 studies were on only five islands, and the range of families and life stages assessed was limited. We also found uneven research into the factors affecting oceanic island amphibians and their responses; analyses involving the effect of temperature on amphibian range expansion or contraction were the most common, with few studies of the effects of salinity. The scarcity and unevenness of research from oceanic islands limit our understanding of the effects of climate and land-use changes on amphibians. We discuss potential reasons for these knowledge gaps and recommend ways to address them, such as more equitable distribution of resources and provision of training and research opportunities for island-based biologists.

Maintaining jaguar Panthera onca subpopulations throughout Mesoamerica is vital to range-wide jaguar conservation. Corcovado National Park in Costa Rica is critical habitat for the Osa Peninsula jaguar subpopulation. There is a debate regarding whether the jaguars in this National Park are in a state of crisis. To examine this, we implemented long-term camera-trap monitoring throughout Corcovado National Park during 2015–2021. Using a spatially explicit Jolly–Seber model we estimated jaguar populations and distribution throughout our study area. Additionally, we reran our model using a constrained study area to compare our findings with those of a previous study. Trends in jaguar abundance indices and population estimates during 2015–2021 indicate that jaguar abundance has increased over time. Our jaguar density estimates also fall within the range of jaguar densities reported for relatively stable populations elsewhere. Using the same study area as that of a prior study, jaguar densities also increased over the duration of our study and were mostly comparable to previous density estimates. Our results suggest that jaguars within Corcovado National Park may not be in a state of crisis. Rather, our findings provide further hope for the jaguars of the Osa Peninsula. They do not, however, diminish the importance of continued conservation efforts. These will remain critical both inside and outside Corcovado National Park, as threats appear to have persisted over time.

The thick-shelled river mussel Unio crassus is categorized as Endangered on the IUCN Red List, and searching for surviving populations is urgent. We surveyed for this species in Kaliningradskaya Oblast, a Russian territory lying between Poland and Lithuania, where empty shells of the species had been reported from two rivers. There are at least 125 rivers and numerous small streams in the region, and as a comprehensive survey of all of these watercourses is infeasible, we used a method developed for surveys of the freshwater pearl mussels Margaritifera margaritifera and Margaritifera laevis. This involved a remote assessment of the forests and lakes in the river basins to identify sites potentially suitable for U. crassus based on criteria used for pearl mussels, followed by site surveys. We surveyed six sites and discovered U. crassus in five of those, only two of which support healthy populations. The existence of other U. crassus populations in Kaliningradskaya Oblast is unlikely. This study underscores the critical role of riparian arboreal vegetation for freshwater mussels. The conservation of U. crassus in rivers surrounded by farmlands is challenging because of siltation, eutrophication and other processes that negatively impact the riverine environment. Even the abandonment of these farmlands does not necessarily lead to improvements in mussel survival. Any plans for the restoration of U. crassus will require concurrent restoration of riparian arboreal vegetation.

Changing human behaviours is a key facet of addressing global environmental issues. There are many factors (i.e. determinants) that could influence whether an individual engages in pro-environmental behaviour, and understanding these determinants can improve efforts to protect and restore the natural environment. However, despite published criticism of poor survey design, there is little practical guidance on how to capture these determinants accurately in closed-answer surveys (those with predefined answer options). A recent literature review summarized behavioural determinants of pro-environmental behaviour. We build on this by providing practical insights into how 17 key pro-environmental behavioural determinants can be measured through closed-answer surveys. We reviewed 177 papers published during 2013–2023 that met the criteria for inclusion. These papers captured 624 measurements of the 17 determinants. We found seven types of question formats used, including scales (Likert scales, semantic scales and a pictorial scale), multiple-choice questions (where respondents could select either one or more answer options), binary questions and ranking questions. We then synthesized design considerations both specifically for each format and more broadly across surveys. These considerations included using validated measures, reducing cognitive burden and biases (e.g. social desirability bias, order effects, recall bias), selecting the question format (e.g. different formats of multiple-choice or binary questions) and using best practices for scale questions. The insights collected through this review provide practical advice for developing closed-answer surveys that robustly and usefully measure key determinants of pro-environmental behaviour.

Big cats are of conservation concern throughout their range, and genetic tools are often employed to study them for various purposes. However, there are several difficulties in using genetic tools for big cat conservation that could be resolved by modern methods of DNA sequencing. Recent reports of the sighting of a putative Javan tiger Panthera tigris sondaica in West Java, Indonesia, highlight some of the difficulties of studying the genetics of big cats. We reanalysed the data of the original reports and found that the conclusions were drawn based on incorrect copies of the genes. Specifically, the nuclear copy of the mitochondrial gene was analysed with the mitochondrial sequence, leading to discordance in the results. However, re-sequencing of the remaining DNA confirms that the sighting could have been that of a tiger, but the subspecies cannot be confirmed. This work highlights the urgency of developing high-throughput sequencing infrastructure in the tropics and the need for reliable databases for the study of big cats.

Iberodes littoralis subsp. gallaecica (Laínz) M. Serrano, R. Carbajal & S. Ortiz is a small annual plant endemic to dune systems in the north-west Iberian Peninsula. It is categorized as Endangered on the IUCN Red List and is a priority taxon under the EU Habitats Directive. Nevertheless, the only comprehensive census of this subspecies was conducted in 2009. Here we present the results of a new survey conducted in 2023 that adds a new location to its known range. Comparison with the previous census suggests that both the total population and area of occupancy have increased. However, these changes were not uniform across the range of the subspecies, with populations increasing at the northern and southern extremes and populations at central sites remaining stable or decreasing. Spatial differences in climate, anthropogenic pressures, plant performance and/or random fluctuations may explain these interpopulation variabilities. Given that the majority of populations are already located within the EU Natura 2000 network, we recommend that the current level of protection be maintained and that the plant be reintroduced into dune systems from which it has recently disappeared. Despite the increase in the total population, we recommend that the plant be recategorized as Critically Endangered given that its area of occupancy is small. Further censuses over time will be needed to provide information on population dynamics, trends, fluctuations and responses to environmental variables.

Chhattisgarh, India, harbours a metapopulation of 250–300 Asian elephants Elephas maximus that has expanded its range from neighbouring states since 2000. Elephants in the state occur across a mosaic of forests interspersed with agricultural settlements, leading to frequent interactions with people, some of which culminate in conflict. We assessed patterns of crop losses as a result of elephant incursions, at two spatial scales. We found widespread crop losses, with 1,426 settlements in and around 10 forest divisions and four protected areas reporting elephant-related crop losses during 2015–2020. At the landscape scale, spanning c. 39,000 km2, intensity of habitat use by elephants, forest cover and number of forest patches explained variations in intensity of crop losses. At a finer spatial scale, covering c. 1,200 km2 of forest–agriculture matrix in Surguja, probability of crop loss was low near roads but high close to forest patches and was also affected by patch heterogeneity. Both male and female elephant groups fed on crops. As areas with high crop losses are also areas used intensively by elephants, management to increase elephant occupancy in relatively large and connected forest patches is imperative, to minimize crop losses and improve elephant conservation. Concomitantly, expansion of elephant range into agricultural areas that lack forests should be discouraged. In forest divisions, options to reduce negative human–elephant interactions include institutionalizing elephant monitoring, transparent and prompt ex gratia payment for crop losses, and the use of portable physical barriers.

The regent honeyeater Anthochaera phrygia is a Critically Endangered Australian songbird, with current population estimates of < 300 individuals remaining in the wild. Low nest success is a factor preventing the recovery of the population, and management remedies are needed. However, a lack of data on intervention success raises uncertainty and impedes planning. To identify management priorities under uncertainty, we engaged with conservation practitioners and key stakeholders to develop and evaluate potential nest protection interventions. Four categories of threats were considered: avian predators, mammalian predators, extreme weather events and avian competitors. The interventions with the highest predicted probabilities of nest success under each threat category were, respectively: lethal control of avian predators, the use of tree collars to control arboreal mammalian predators, the provisioning of supplementary food and nesting resources during extreme weather events, and control of the noisy miner Manorina melanocephala, a competitor species. Our analysis shows that by applying a combination of conservation actions alongside improvements in nest detection, it is possible, based on the opinion of experts, to provide a pathway for the recovery of the regent honeyeater.