Female-biased introductions produce higher predicted population size and genetic diversity in simulations of a small, isolated tiger (Panthera tigris) population

Isolation of wildlife populations represents a key conservation challenge in the twenty-first century. This may necessitate consideration of translocations to ensure population viability. We investigated the potential population and genetic trajectory of a small, isolated tiger (Panthera tigris) population in Thailand’s Dong Phayayen-Khao Yai forest complex across a range of scenarios. Using an individual-based, spatially-explicit population modelling approach, we simulate population and genetic trajectories and evaluate the relative impact of translocations from a related population. Population and genetic trajectories in our study were most sensitive to sex and number of individuals translocated and translocation frequency. Translocation of females produced consistently higher population, allelic richness, and heterozygosity compared to equal numbers of males. Despite population increases, declines in allelic richness and heterozygosity across simulations were stark, with simulations predicting a mean decline of allelic richness and heterozygosity of 46.5% and 53.5% without intervention, respectively. Translocations of four females every generation or every other generation were required to prevent substantial heterozygosity declines. While translocations could increase population size, they may fail to prevent long-term loss of genetic diversity in small populations unless applied frequently. This reinforces the importance of incorporating realistic processes of genetic inheritance and gene flow in modelling small populations

Reviving the Arabian leopard: harnessing historical data to map habitat and pave the way for reintroduction

The Arabian leopard (Panthera pardus nimr) has experienced dramatic range and population contractions over the last century. Conservation efforts for this felid focused on captive breeding and identification of suitable conditions for reintroductions. With this study, we unravelled historical collaring and direct observations data to understand the spatial use of the last leopards recorded in the region of Israel and the West Bank (IWB). Through datasets of leopard occurrence, we characterised suitable habitats, assessed niche overlap with the Arabian leopard's main prey, the Nubian ibex (Capra nubiana), and evaluated their distributions with respect to currently protected habitats. We estimated home-ranges employing area-corrected density kernel methods and investigated suitable conditions through multiple scales habitat modelling. Average home ranges for the population were 73.24 ± 47.91 km2 and 77.46 ± 54.94 km2, depending on the time lag adopted. Ecological response to predictors highlighted reliance by both predator and prey on the same habitat characteristics, suggesting they occupied essentially identical niches. These characteristics were intermediately rugged topographic conditions and high indices of vegetation in scarcely populated desert environments, mostly encompassed within protected areas. The distribution of leopard and ibex overlapped substantially according to several metrics. Notably, more than half of potential habitat for both species is encompassed by protected areas and military zones. Given the coincidence in their ecological requirements, and highly congruent distributions, an important step towards future reintroduction of Arabian leopards will include gaining a better understanding of ibex populations, alongside attention to the practicality of enforcing habitat protection

A multi-scale, multivariate habitat selection model demonstrates high potential for the reintroduction of the clouded leopard (neofelis nebulosa) to Taiwan

Hunting, habitat loss and fragmentation have driven a rapid decline in the distribution and abundance of the clouded leopard, Neofelis nebulosa, across its range, and in several areas the species is now extirpated, including Taiwan. Taiwan, an historical stronghold of the species, is a candidate for expanding its current range by reintroduction, based on increasing prey abundance and high forest coverage. Such future reintroduction efforts, however, are hampered by the lack of an empirical analysis of clouded leopard habitat potential in the island. To address this knowledge gap, this study explores the species’ habitat suitability in Taiwan. We employed a multi-scale multivariate habitat selection model based on clouded leopard presence-absence data from extensive camera trap surveys across its current range, and extrapolated the result to predict suitable habitats in Taiwan. Our results reveal that 40% of Taiwanese territory represents suitable habitats for clouded leopards and of which 90% is under protection. This demonstrates the robust potential of Taiwan’s habitat for clouded leopard reintroduction

Seventy-two models of large mammal connectivity across Panama: insights into a critical biogeographic linkage zone

AimThe goal of this study was to evaluate consistency among multiple connectivity models for jaguar and puma across Panama to evaluate the plausible current patterns of habitat connectivity for these and potentially other species in this critical biogeographic linkage zone.ApproachWe compared 72 different models of landscape connectivity for both large felids using both empirically based and expert opinion derived resistance layers. We conducted resistant kernel modeling with different dispersal abilities to reflect uncertainty in the movement potential of the two species. We applied three transformations to the resulting connectivity surfaces to account for uncertainty about the shape of the dispersal kernel function. We then evaluated the similarities and differences among these connectivity models, identifying several factors that drive their differences. We quantified the factors that drive differences in connectivity predictions using surface correlation, Mantel testing, and agglomerative hierarchical clustering.ResultsWe found that the main differences among predicted connectivity surfaces were related to species and resistance modeling approach, with relatively little consistent difference related to dispersal ability and nonlinear kernel transformation. Based on the ensemble connectivity prediction across the 72 models, we identified two major core areas, corresponding to the eastern and western portions of the central mountain range, significant attenuation of connectivity in lowland and developed areas of Panama, a major breakage in connectivity in the Canal Zone spanning the width of the country, and weak but potentially critical movement routes connecting the two core areas across the Canal Zone.ImplicationsThis paper contributes to both a theoretical and practical understanding of the functional connectivity of large felids, confirming the strong effect of differences in source points and resistance surfaces on connectivity predictions and identifying and mapping key core areas, barriers, and potential corridors for carnivore movement across the critical Pan-American linkage of the Isthmus of Panama

Land use change in three Carpathian communities (Niedźwiedź, Szczawnica and Trzciana) in the second part of the 20th century

Celem niniejszej pracy jest określenie kierunków zmian użytkowania ziemi w ostatnim trzydziestoleciu XX wieku, w Karpatach, na przykładzie trzech gmin (Niedźwiedź, Szczawnica i Trzciana). Materiałem źródłowym dla przeprowadzanych badań były czarno-białe zdjęcia lotnicze (lata 70.) i ortofotomapy (rok 2003). Przeprowadzone analizy wykazały wzrost powierzchni leśnej, nieużytków z obszarami porzuconymi oraz obszarów zabudowanych i infrastruktury technicznej a także spadek powierzchni obszarów użytkowanych rolniczo. Największą dynamiką zmian charakteryzowały się obszary poniżej 600-700 m n.p.m. na stokach o nachyleniach poniżej 10C.The aim of this paper is to analyse the main trends in land use change in the last thirty years of the 20th century in the Carpathians, based on the assessment of change in three communities: Niedźwiedź, Szczawnica and Trzciana. The research focused on two points in time; the 1970s and the year 2003. The sources of information about land use in the periods analysed period were aerial photographs (1970s) and orthophotomaps (2003). The results show an increase in forest cover, the abandonment of land and built-up areas, and a decrease in agricultural land. The most dynamic changes occurred in the areas below 600-700 m a.s.l. and on slopes below 10C

Multi-scale, multivariate community models improve designation of biodiversity hotspots in the Sunda Islands

Species occur in sympatric assemblages, bound together by ecological relationships and interspecific interactions. Borneo and Sumatra host some of the richest assemblages of biota worldwide. The region, however, faces the highest global deforestation rates, which seriously threaten its unique biodiversity. We used a large camera trap dataset that recorded data for 70 terrestrial species of mammals and birds, to explore the drivers of regional species richness patterns. Using a multi-scale, multivariate modelling framework which quantified the main environmental factors associated with patterns of biodiversity, while simultaneously assessing individual relationships of each species, we determined the ecological drivers of sampled biodiversity, and their contributions to community assemblages. We then mapped predicted species richness, evaluated the effectiveness of protected areas in securing biodiversity hotspots, performed gap analysis to highlight biodiverse areas lacking protection and compared our predictions with species richness maps produced by using IUCN range layers. Finally, we investigated the performance of each species as an indicator of sampled biodiversity. We demonstrate that biodiversity in Borneo and Sumatra is primarily affected by gradients of ecological and anthropogenic factors, and only marginally by topographic and spatial factors. In both islands, species are primarily associated with elevational gradients in vegetation and climate, leading to altitudinal zonation in niche separation as a major factor characterizing the islands' biodiversity. Species richness was highest in north-eastern Borneo and in western Sumatra. We found that most predicted biodiversity hotspots are not formally protected in either island; only 9.2 and 18.2% of the modelled species richness occurred within protected areas in Borneo and Sumatra, respectively. We highlighted that our prediction for Borneo performed better than, and differed drastically from, the IUCN species richness layer, while for Sumatra our modelled species richness layer and the IUCN one were similar, and both showed low predictive power. Our analysis suggests that common and generalist carnivores are the most effective indicators of sampled biodiversity and have high potential as focal, umbrella or indicator species to assist multi-species vertebrate conservation planning. Understanding existing drivers and patterns of biodiversity is critical to support the development of effective community conservation strategies in this rapidly changing region

Integrating Sunda clouded leopard (Neofelis diardi) conservation into development and restoration planning in Sabah (Borneo)

Changes in land use/cover are the main drivers of global biodiversity loss, and thus tools to evaluate effects of landscape change on biodiversity are crucial. In this study we integrated several methods from landscape ecology and landscape genetics into a GIS-based analytical framework, and evaluated the impacts of development and forest restoration scenarios on landscape connectivity, population dynamics and genetic diversity of Sunda clouded leopard in the Malaysian state of Sabah. We also investigated the separate and interactive effects of changing mortality risk and connectivity. Our study suggested that the current clouded leopard population size is larger (+26%) than the current carrying capacity of the landscape due to time lag effects and extinction debt. Additionally, we predicted that proposed developments in Sabah may decrease landscape connectivity by 23% and, when including the increased mortality risk associated with these developments, result in a 40–63% decrease in population size and substantial reduction in genetic diversity. These negative impacts could be mitigated only to a very limited degree through extensive and targeted forest restoration. Our results suggest that realignment of roads and railways based on resistance to movement, without including mortality risk, might be misleading and may in some cases lead to decrease in population size. We therefore recommend that efforts to optimally plan road and railway locations base the optimization on effects of development on population size, density and distribution rather than solely on population connectivity

Multi-scale habitat modelling identifies spatial conservation priorities for mainland clouded leopards (Neofelis nebulosa)

Aim Deforestation is rapidly altering Southeast Asian landscapes, resulting in some of the highest rates of habitat loss worldwide. Among the many species facing declines in this region, clouded leopards rank notably for their ambassadorial potential and capacity to act as powerful levers for broader forest conservation programmes. Thus, identifying core habitat and conservation opportunities are critical for curbing further Neofelis declines and extending umbrella protection for diverse forest biota similarly threatened by widespread habitat loss. Furthermore, a recent comprehensive habitat assessment of Sunda clouded leopards (N. diardi) highlights the lack of such information for the mainland species (N. nebulosa) and facilitates a comparative assessment. Location Southeast Asia. Methods Species–habitat relationships are scale‐dependent, yet <5% of all recent habitat modelling papers apply robust approaches to optimize multivariate scale relationships. Using one of the largest camera trap datasets ever collected, we developed scale‐optimized species distribution models for two con‐generic carnivores, and quantitatively compared their habitat niches. Results We identified core habitat, connectivity corridors, and ranked remaining habitat patches for conservation prioritization. Closed‐canopy forest was the strongest predictor, with ~25% lower Neofelis detections when forest cover declined from 100 to 65%. A strong, positive association with increasing precipitation suggests ongoing climate change as a growing threat along drier edges of the species’ range. While deforestation and land use conversion were deleterious for both species, N. nebulosa was uniquely associated with shrublands and grasslands. We identified 800 km2 as a minimum patch size for supporting clouded leopard conservation. Main conclusions We illustrate the utility of multi‐scale modelling for identifying key habitat requirements, optimal scales of use and critical targets for guiding conservation prioritization. Curbing deforestation and development within remaining core habitat and dispersal corridors, particularly in Myanmar, Laos and Malaysia, is critical for supporting evolutionary potential of clouded leopards and conservation of associated forest biodiversity.Dr. Holly Reed Conservation Fund; Langtang National Park; World Animal Protection; Robertson Foundation; Point Defiance Zoo & Aquariu

Landscape-scale benefits of protected areas for tropical biodiversity

We are indebted to numerous local communities, PA and government agency staff, research assistants, and other partners for supporting the field data collection. Research permissions were granted by appropriate forestry and conservation government departments in each country. Special thanks is given to the Sarawak State Government, Sarawak Forestry Corporation, Forest Department Sarawak, Sabah Biodiversity Centre, the Danum Valley Management Committee, the Forest Research Institute Malaysia (FRIM), the Smithsonian Institute and the Tropical Ecology Assessment and Monitoring (TEAM) network, Sarayudh Bunyavejchewin, and Ronglarp Sukmasuang. Support was provided by the United Nations Development Programme, NASA grants NNL15AA03C and 80NSSC21K0189, National Geographic Society’s Committee for the Research and Exploration award #9384–13, the Australian Research Council Discovery Early Career Researcher Award DECRA #DE210101440, the Universiti Malaysia Sarawak, the Ministry of Higher Education Malaysia, Nanyang Technological University Singapore, the Darwin Initiative, Liebniz-IZW, and the Universities of Aberdeen, British Columbia, Montana, and Queensland.Peer reviewedPostprin

Predicting biodiversity richness in rapidly changing landscapes: climate, low human pressure or protection as salvation?

Rates of biodiversity loss in Southeast Asia are among the highest in the world, and the Indo-Burma and South-Central China Biodiversity Hotspots rank among the world’s most threatened. Developing robust multi-species conservation models is critical for stemming biodiversity loss both here and globally. We used a large and geographically extensive remote-camera survey and multi-scale, multivariate optimization species distribution modelling to investigate the factors driving biodiversity across these two adjoining biodiversity hotspots. Four major findings emerged from the work. (i) We identified clear spatial patterns of species richness, with two main biodiverse centres in the Thai-Malay Peninsula and in the mountainous region of Southwest China. (ii) Carnivores in particular, and large ungulates to a lesser degree, were the strongest indicators of species richness. (iii) Climate had the largest effect on biodiversity, followed by protected status and human footprint. (iv) Gap analysis between the biodiversity model and the current system of protected areas revealed that the majority of areas supporting the highest predicted biodiversity are not protected. Our results highlighted several key locations that should be prioritized for expanding the protected area network to maximize conservation effectiveness. We demonstrated the importance of switching from single-species to multi-species approaches to highlight areas of high priority for biodiversity conservation. In addition, since these areas mostly occur over multiple countries, we also advocate for a paradigmatic focus on transboundary conservation planning.The majority of the team, as well as the data, were part of the core WildCRU effort supported principally by a Robertson Foundation grant to DWM