This study examines mortality of the Amur tiger Panthera tigris altaica caused by traffic collision incidents in the Russian Far East from 1980 to 2023. Forty-six per cent of mortality incidents occurred within the last 4 years of this period (2020–2023) following an outbreak of African swine fever, which led to a reduction of prey available for tigers. Using multiple regression analysis, we identify significant predictors of tiger mortality, including road type, biotope, and distances to settlements and federally protected areas. We identified five locations with concentrations of tiger mortality, with four of these near protected areas comprising 54% of all incidents. Asphalt roads have an elevated risk of tiger deaths during the winter, whereas unpaved roads have elevated risk during warmer months. Wildlife-friendly road planning, including crossings and enhanced night-time controls, is crucial for reducing mortality and ensuring the survival of this species amidst increasing development of human infrastructure. This study highlights the urgent need for targeted conservation efforts to reduce traffic-related risks to the Amur tiger.

Understanding the population structure and genetic diversity of green turtles is crucial for effective conservation. This study investigated the occurrence, genetic composition, and potential origins of green turtles (Chelonia mydas) in the Potiguar Basin, northeastern Brazil, based on stranding data from 2010 to 2019. Analysis revealed that 87.36% of the population consisted of juveniles, primarily females with a curved carapace length (CCL) between 30 and 59.9 cm. Genetic analysis of the mtDNA control region (481 bp, n = 39) revealed eight haplotypes, with CM-A8 (48.7%) and CM-A5 (30.8%) being the most common. This may be related to the geographic position of the Potiguar Basin, located in the ‘corner’ of the South American continent. High haplotype diversity and low nucleotide diversity were observed, consistent with other Brazilian foraging grounds. Mixed stock analysis identified Ascension Island as the primary source population, followed by Guinea-Bissau and Surinam. The results highlight the importance of the Potiguar Basin as a foraging area for green turtles and emphasize the need for comprehensive conservation strategies to protect this vulnerable population.

Land-use changes are considered one of the main drivers of biodiversity loss. Agricultural intensification, pastoral abandonment, and changes in forest management have led to the homogenisation of landscapes. In particular, the encroachment of grasslands and the densification of forests that are no longer pastured threaten species that require multiple habitats to nest and forage, such as the European Nightjar Caprimulgus europaeus. Whereas previous studies have focused on understanding factors influencing the decrease of nightjars at regional or national scales, here, we aimed to assess fine-scaled habitat selection by nightjars within nesting and foraging sites based on high-resolution GPS tracking data. Vegetation structure and composition were quantified in the field. In the nesting habitat, nightjars prefer open forests with a low percentage of trees and where the ground is not covered by more than 40% of grass and crawling bushes (dwarf bushes such as Juniperus species). In contrast, when foraging, nightjars select open grasslands and biodiversity-friendly managed vineyards, both richly structured, i.e. interspersed or surrounded by other land-use types such as hedges or isolated trees. Both the nesting and foraging habitats are currently threatened, either by the abandonment of forest management, which makes stands denser and more homogeneous, or through agricultural intensification, which reduces land-use diversity. Clear habitat-specific management recommendations and political incentives are needed to simultaneously preserve and/or restore these critical habitats, which are important for nightjars that use complementary resources for nesting and foraging.

Owing to habitat loss, the entire breeding population of the globally threatened Aquatic Warbler Acrocephalus paludicola, a flagship bird species of fen mires, is now limited to scattered areas in east-central Europe. The breeding biology of the Aquatic Warbler was studied between 2012 and 2015 in calcareous fens dominated by the Cladietum marisci sedge community at the south-western range limit of the species, near Chełm, in south-east Poland. Two nesting peaks were observed during the breeding season, corresponding to first and second breeding attempts. Nest densities were greater during the first- rather than the second-brood period but singing male densities did not differ between the brood periods. Clutch size and post-hatching fledging success were significantly lower during the second-brood period. Total nest fledging success (whether or not a nest fledged at least one young) was 76.6% in 124 nests with known outcomes with an average of 2.7 (± SE 0.2) fledglings per nest. Mayfield probability of nest survival was 56.9% with losses mainly due to predation (55%), nest desertion or female predation (28%), and changes in water level (14%). Nest survival to fledging increased along the gradient of increasing levels of litter layer thickness, stagnating water, and vegetation height at the nest, and increasing height of the nest above the soil. Fledgling production tended to be lower than in the Biebrza Marshes (north-east Poland) habitats, assumed to be optimal for breeding. Otherwise, the reproductive success estimates did not deviate from nests found in the core breeding areas in north-east Poland or Belarus. Brood feeding frequency (15.5 ± 1.0/hour) was similar to that observed in the Biebrza Marshes. Our results suggest that the calcareous fens at the margins of the current species’ range provide a suitable breeding habitat. However, as the nesting area has contracted, management programmes tailored to the ecological requirements of the Aquatic Warbler are required.

Historiographic studies of transnational environmental law (TEL) are increasingly relevant as scholars and practitioners search for ways in which to deliver more quickly and efficiently effective regulation that is responsive to global environmental issues. This article uses new and original archival research to better locate the Convention for the Preservation of Wild Animals, Birds and Fish in Africa (1900 London Convention) in its legal-scientific historical context. Most of the scholarship on this topic draws on historian John M. MacKenzie's groundbreaking analysis of what he called ‘the hunting cult’ and its role in the imperial advance into India, Africa, and elsewhere. When viewed through the dual lens of legal history and the history of science, the late 19th and early 20th centuries represented a period of transition during which a new science-based perspective advanced by evolutionary biologists was embraced by science-minded policymakers, and expressed in domestic law and foreign policy aimed at the preservation of endangered species and the protection of biodiversity. The 1900 London Convention is an early example of a modern TEL instrument informed by science and by values that today most recognize as being critically important and universal. The new history in this article also resonates as an example of how polarizing political narratives can delay law reform and the importance of maintaining focus on collaborative problem solving and science-based regulation of complex transnational environmental issues.

Gecarcinid crabs have their life cycles in antagonistic scenarios, with their larvae developing in the sea and the juvenile/adult phases occurring on land. Adults migrate from land to sea to release their larvae, which return to land upon reaching the megalopa stage. Recruitment and early instar traits in gecarcinids crabs remain unknown, leading to some species lacking age-specific information. Despite massive recruitment observed in some insular gecarcinid species (e.g. Gecarcoidea natalis), recruits are generally expected to be few and exhibit cryptic behaviour, potentially occupying the burrows of conspecifics. We evaluated whether recruits of Johngarthia lagostoma on Trindade Island, Brazil, co-inhabit larger conspecific burrows, analysing this occurrence and examining their growth patterns, density, and body size across different lunar phases. Johngarthia lagostoma recruits inhabit conspecific burrows, either abandoned or occupied by adult crabs, but always with leaves stored in the inner chamber. Recruits in co-inhabiting behaviour reach a maximum carapace width of 7.3 mm, and after that, they are likely detected by the adults and possibly cannibalized or leave burrows naturally. During the full moon, the higher density and smaller size of recruits were recorded, indicating a recruitment lunar phase. It is crucial to ascertain the prevalence of co-inhabitation behaviours in other land crab species to expand the knowledge about recruitment patterns in these key community species.

Heat stress from high temperatures has been recognised as a threat to several bird species and one that is likely to increase in severity and frequency as a result of global environmental change. Many seabirds are particularly vulnerable as their adaptations to forage in cold water can make it hard for them to resist heat gain while on land. The African Penguin Spheniscus demersus forages in cool water (10–20°C) but breeds and moults on land where temperatures can exceed 30°C. Little is known about its thermal physiology and when heat stress will occur. Here, we provide the first account of changes in body temperature and behaviour in African Penguins in response to an experimental increase in ambient temperature from 20°C to 35°C. Surprisingly, the highest body temperature observed (39.2°C) was recorded at the start of the study. Presumably, this response in body temperature was due to the stress of transport and handling. Penguins returned to normal body temperature (37.3°C) after 3.5 hours and maintained normothermia for roughly an hour. We then observed the onset of heat storage at an ambient temperature of 29°C, whereafter body temperature increased steadily at a rate of ca.0.2°C per 1°C increase in ambient temperature. Panting commenced at an ambient temperature of 31.4°C, when body temperature was 37.8°C. In addition to panting, penguins changed their posture to facilitate heat dissipation by standing, raising their heads, and extending their flippers. Our results corroborate field observations and support the argument that African Penguins are highly vulnerable to heat stress in the near future as extreme heat events become more severe and frequent due to climate change. Our results also confirm that penguins are sensitive to handling, which elicits a hyperthermic response. Given the general sensitivity of penguins to disturbance, from a conservation perspective, we advise that cautionary measures be implemented at colonies during critical life-history stages.

Detecting factors causing the decline of wildlife populations provides essential knowledge for their effective conservation. Populations of Black Stork Ciconia nigra are decreasing in northern Europe; however, there are no detailed analyses of its survival, which frequently is a key demographic parameter affecting population dynamics in long-lived species. We used long-term data from re-sighted colour-ringed birds and satellite-tracked birds to estimate age- and sex-specific survival in a rapidly declining Black Stork population in the Baltic region at the northern end of the European range. Apparent survival (0.89) among colour-ringed birds older than one year was not significantly different from the previously reported estimates in Central Europe and the estimated real survival of GPS-tracked birds (0.77). However, the apparent survival of first-year (1y) birds was only 0.04, which is remarkably lower than earlier estimates in Central Europe. The real survival of GPS-tracked 1y birds was somewhat higher (0.11), but still much lower than estimates in other long-lived species. Apparent survival was three times lower in 1y females (0.013) than 1y males (0.045); this could be explained in part by a higher mean natal dispersal of females (189.1 km), compared with that of males (72.0 km), as well as by sex-specific mortality due to poor foraging conditions. There were no significant differences in apparent survival between the male and female storks older than one year. To better address the population decline, further research is needed to determine the factors causing low survival in young Black Storks, including the roles of food availability and climate change.

A 30 years long data series on the infection dynamics of European eel (Anguilla anguilla L.) with the non-native invasive nematode Anguillicola crassus Kuwahara, Niimi & Hagaki, 1974 is presented. Parasite burden was evaluated for 30 years in inland and coastal waters in Mecklenburg-Western Pomerania from 1991 to 2020. The total prevalence, mean intensity and damage status of the swim bladders were very high during the first decade (1991–2000), and significantly decreased in both marine and freshwater eel populations in the following decades (2001–2010, 2011–2020). The parasite intensity of eels in coastal waters was significantly lower compared with the freshwater systems (61.3% vs 79.5% in the first decade), indicating the vulnerability of the parasites to brackish water conditions and the fact that the life cycle of A. crassus cannot be completed under high saline conditions. Eel caught in the western part of the Baltic Sea (west of Darss sill) had the lowest mean infection (51.8% in first decade) compared to the eastern part with 63.8%. Thus, besides different infection patterns caused by the environmental conditions, a temporal trend towards a reduced parasite intensity and a more balanced parasite–host relationship developed in the 30 years of interaction after the first invasion. Possible reasons and mechanisms for the observed trends in parasite–host interactions are discussed.

The sicklefin devil ray (Mobula tarapacana) is a large, pelagic ray which is listed as Endangered by the International Union for Conservation of Nature (IUCN). Mobula tarapacana is thought to have a circumglobal, yet patchy distribution, and has not been verified extant off the eastern USA. Here, we report 180 sightings of M. tarapacana with a total of 361 individuals, collated across five datasets from aerial survey operations and incidental sightings in the waters off the US East Coast and Gulf of Mexico, between 1996 and 2022. This study extends the northern range of M. tarapacana in the Gulf of Mexico to 29°N, and in the Atlantic to 40°N. Seasonal trends were observed off the north-eastern coast of the USA, with M. tarapacana only present in the summer months. Measurements from high resolution digital aerial imagery found M. tarapacana off the New York coast to be adults and subadults with an average disc width of 268 cm (±25, range 232–316 cm). This study provides important spatial and temporal data for management, as well as informing areas for future research on M. tarapacana in the western Atlantic.

In 2015 and 2016 four Lesser White-fronted Geese (Anser erythropus), a globally threatened species, were caught and tagged during spring migration representing nearly 10% of the entire Swedish breeding population at the time. Two of the birds were followed over more than one season. Tracking data revealed an unexpected wide network of migration corridors and staging sites. Autumn and spring migration differed by stepping-stone sites and migration speed. So far unknown key stopover sites were discovered in Denmark, northern Germany, and Sweden. By using dynamic Brownian bridge movement models, the potential areas that Lesser White-fronted Geese used during migration are described and conservation implications spotlighted. This study provides another important piece of the puzzle describing the migration of Lesser White-fronted Geese in Western Europe.

The behaviour of a captive pair of clouded leopards was studied during a series of manipulations in order to devise a safe method of introduction for mating purposes. Manipulations consisted of allowing each individual unrestricted access to the other's outdoor enclosure, initially in the absence of the other individual, but culminating in joint access. Dominant activities involved sitting, lying, grooming, and adopting a low profile amongst the vegetation. The female tended to be more arboreal than the male, although both cats spent most of their time on the ground. The male marked various sites by foot-scrubbing (1-4% occurrence), which involved shuffling urine into the ground using his hind feet. This was less common in the female (<1%). Male foot-scrubbing was most frequent on introduction nights, and in the female's enclosure. Both sexes exhibited cheek-marking behaviour, although it was more common in the male. The frequency of male cheek-marking increased in response to urine production by the female. Observations during introductions suggested that the male may assess the female's reproductive condition by stimulating her to urinate. The most marked changes in the behaviour occurred between control and introduction nights. The larger male took the initiative, and the female appeared extremely wary of his presence, striking out with her claws if he approached too closely. Although the individuals did not mate during the introductions, the method of gradual acquaintance through an experimentally induced overlap of ‘home ranges’ was effective, as the female was not injured even though the male had a history of aggression.

Herds of white-lipped peccary (Tayassu pecari) have historically been kept in captivity in order to replace stocks lost to hunting however the lack of knowledge regarding their species-typical behaviour remains an impediment to understanding their captive needs. Environmental enrichment has been suggested as an efficient way of decreasing aggression and apathy as well as increasing the expression of normal behavioural acts — such as play behaviour — which may, in turn, contribute to improved husbandry conditions. Therefore, the aims of this study were to describe play behaviour in this species and analyse the effects of environmental enrichment on such behaviour as well as on agonistic expression and inactivity. The occurrence of solitary and social play acts were recorded, as well as agonistic interactions and inactivity (resting positions) in two conditions (non-enriched and enriched with ball, hose and see-saw). This study included 24 captive peccaries three of which were juveniles, nine sub-adults and 12 adults, with a 1:1 sex ratio. The relationship between social dominance hierarchy and play behaviour was also analysed in each observational condition. Enrichment resulted in increased solitary and social acts of playing both in juvenile/sub-adult and adult peccaries. All the individuals played with the introduced objects and spent less time in resting positions throughout the enrichment phase. However, no decrease in agonistic interactions was observed and dominant individuals played more with the objects. Our study showed that environmental enrichment stimulated play behaviour in white-lipped peccaries as well as decreasing levels of inactivity; this may lead to improvements in the welfare of individuals in captive breeding centres.

Adult sex ratios (ASRs) have proved to correlate with population trends, which make them potential useful indicators of a species’ population trajectory and conservation status. We analysed ASRs and proportion of juveniles in flocks of an endangered steppe bird, the Little Bustard Tetrax tetrax, using surveys made during the non-breeding period in seven areas within its Western European range (one in Portugal, four in Spain, and two in France). We found overall male-biased ASRs, as all the seven surveyed areas showed a male-biased ASR mean value. Five areas were below the threshold median value (female sex ratio = 0.4) considered to be consistent with an increased probability of extinction, according to earlier population viability analyses for the species. We also found a significant positive correlation between female ratio and the proportion of young individuals in the non-breeding flocks surveyed. Our results (strongly male-biased ASRs) support the hypothesis that the viability of Little Bustard populations in Western Europe is threatened by an excess of female mortality, something that should be quantified in the future, and emphasise the value of monitoring sex ratio as a population viability indicator in species where monitoring survival is difficult to achieve.

Nothofagus alessandrii, categorized as Endangered on the IUCN Red List, is an endemic, deciduous tree species of the coastal range of central Chile. We assessed the effects of fire severity, invasion by the exotic fire-prone Pinus radiata, and land-cover composition and configuration of the landscape on the resilience of fragments of N. alessandrii after a mega-fire in 2017. We used remote sensing data to estimate land-use classes and cover, fire severity and invasion cover of P. radiata. We monitored forest composition and structure and post-fire responses of N. alessandrii forests in situ for 2 years after the mega-fire. In the coastal Maule region wildfires have been favoured by intense drought and widespread exotic pine plantations, increasing the ability of fire-adapted invasive species to colonize native forest remnants. Over 85% of N. alessandrii forests were moderately or severely burnt. The propagation and severity of fire was probably amplified by the exotic pines located along the edges of, or inside, the N. alessandrii fragments and the highly flammable pine plantations surrounding these fragments (> 60% of land use is pine plantations). Pinus radiata, a fire-adapted pioneer species, showed strong post-fire recruitment within the N. alessandrii fragments, especially those severely burnt. Positive feedback between climate change (i.e. droughts and heat waves), wildfires and pine invasions is driving N. alessandrii forests into an undesirable and probably irreversible state (i.e. a landscape trap). A large-scale restoration programme to design a diverse and less flammable landscape is needed to avoid the loss of these highly threatened forest ecosystems.

Regional and local studies suggest that the Tufted Puffin Fratercula cirrhata in North America is declining in portions of its range. However, whether the overall population is declining, or its range is contracting with little change to the overall population size, is unknown. To examine population trends throughout its North American range, we assembled 11 datasets that spanned 115 years (1905–2019) and included at-sea density and encounter estimates and at-colony burrow and bird counts. We assessed trends for the California Current, Gulf of Alaska, and Bering Sea/Aleutian Islands large marine ecosystems (LME). We found: (1) nearly uniform and long-term declines of Puffins breeding in the California Current ecosystem, with most ecosystem colonies surveyed, (2) declining trends at two large colonies and in one at-sea dataset in the Gulf of Alaska LME, with the fourth smaller colony exhibiting no significant trend, and (3) positive trends at four out of five colonies in the Bering Sea/Aleutian Islands ecosystem complex, with no detectable trend at the fifth very large colony. The general pattern of Tufted Puffin declines across the California Current and Gulf of Alaska LMEs may be attributable to a variety of factors, but additional study is needed to evaluate the relative influence of potential population drivers both independently and synergistically. Potential mechanisms driving population increases in the Bering Sea/Aleutian Islands ecosystem include reduced depredation and bycatch, intrinsic population growth, and immigration. We found strong evidence for declines in two of the three LMEs evaluated representing approximately three quarters of the species’ North American range. This region of decline includes the Gulf of Alaska LME, which contains a significant portion of the species’ estimated total North American population. Despite data limitations, our analysis coupled with more focused and local studies indicates that the Tufted Puffin is a species of conservation concern.

The suitable habitats of the Endangered Green Peafowl Pavo muticus have declined by 80% over the past century due to extensive anthropogenic degradation. Currently, only six strongholds remain in mainland South-east Asia. While there are estimates of the species’ presence and status in five of these, the sixth one, defined as an “expected stronghold” located in the suitable dry forest along the Salawin River between Thailand and Myanmar, is not well documented. This study assessed the status of the area as a stronghold for the Green Peafowl’s long-term survival by estimating 1) the population density, 2) the current extension of suitable habitats, and 3) the threats to its survival. The area had an estimated density of 0.27 calling males/km2 (CI = 0.07–1.01) inhabiting 9,154 km2 of a mosaic of forest types, including mixed dry pine, mixed deciduous, and dry dipterocarp forests. Higher estimates were reported in other strongholds, including 0.8 birds/km2 in Bago Yoma (Myanmar), 15.8 birds/km2 in north-east Thailand, 1.13–11.34 birds/km2 in HuaiKhaKhaeng Wildlife Sanctuary (Thailand), 0.15–1.7 birds/km2 in northern Cambodia, and 0.15–4.69 birds/km2 in eastern Cambodia / south-central Vietnam. Hunting, habitat disturbance, and the presence of humans posed the greatest danger to the species across the surveyed area. Our results confirm the potential of the area for the species’ long-term survival. However, this “expected stronghold,” which could sustain a population of over 10 calling males/km2 like other high-quality strongholds, is in dire need of a comprehensive management plan to help reduce anthropogenic pressure. Ultimately, transboundary management between Thailand and Myanmar is crucial for the long-term repopulation of this stronghold.