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"MCCARTHY, THOMAS M."
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Modelling potential habitat for snow leopards (Panthera uncia) in Ladakh, India
The snow leopard Panthera uncia is an elusive species inhabiting some of the most remote and inaccessible tracts of Central and South Asia. It is difficult to determine its distribution and density pattern, which are crucial for developing conservation strategies. Several techniques for species detection combining camera traps with remote sensing and geographic information systems have been developed to model the habitat of such cryptic and low-density species in challenging terrains. Utilising presence-only data from camera traps and direct observations, alongside six environmental variables (elevation, aspect, ruggedness, distance to water, land cover, and prey habitat suitability), we assessed snow leopard habitat suitability across Ladakh in northern India. This is the first study to model snow leopard distribution both in India and utilising direct observation data. Results suggested that elevation and ruggedness are the two most influential environmental variables for snow leopard habitat suitability, with highly suitable habitat having an elevation range of 2,800 m to 4,600 m and ruggedness of 450 m to 1,800 m. Our habitat suitability map estimated approximately 12% of Ladakh's geographical area (c. 90,000 km2) as highly suitable and 18% as medium suitability. We found that 62.5% of recorded livestock depredation along with over half of all livestock corrals (54%) and homestays (58%) occurred within highly suitable snow leopard habitat. Our habitat suitability model can be used to assist in allocation of conservation resources by targeting construction of livestock corrals to areas of high habitat suitability and promoting ecotourism programs in villages in highly suitable snow leopard habitat.
Journal Article
Status of the mountain ungulate prey of the Endangered snow leopard Panthera uncia in the Tost Local Protected Area, South Gobi, Mongolia
The availability of wild prey is a critical predictor of carnivore density. However, few conservation programmes have focused on the estimation and monitoring of wild ungulate populations and their trends, especially in the remote mountains of Central Asia. We conducted double-observer surveys to estimate the populations of ibex Capra sibirica and argali Ovis ammon in the mountainous regions of Tost Local Protected Area, South Gobi province, Mongolia, which is being considered for designation as a Nature Reserve. We also conducted demographic surveys of the more abundant ibex to examine their sex-ratio and the survival of young during 2012–2013. The estimated ibex population remained stable in 2012 and 2013 and the estimated argali population increased from 108 in 2012 to 230 in 2013. The biomass of wild ungulates was c. 6% that of livestock. Mortality in young ibex appeared to increase after weaning, at the age of 12 months. We estimated the population of wild ungulates was sufficient to support 14–18 adult snow leopards Panthera uncia. The adult snow leopard population in our study area during 2012–2013, estimated independently using camera-trap-based mark–recapture methods, was 12–14. Based on our results we identify the Tost Local Protected Area as an important habitat for the conservation of these ungulates and their predator, the Endangered snow leopard, and recommend elevation of its status to a Nature Reserve.
Journal Article
Aquatic Hermaphrodite Snails Exposed to Polychlorinated Biphenyls (PCBs) Experience Increased Mortality, Reduced Reproduction, and Endocrine Disruption
Populations of freshwater gastropods are decreasing globally. To investigate one aspect of decline, we exposed the benthic dwelling hermaphroditic snail Planorbella (= Helisoma) trivolvis (Say) (Marsh Rams-horn) to polychlorinated biphenyls (PCBs). Marsh Rams-horn is a simultaneous hermaphrodite, suggesting that disruption of reproductive success is independent of snail interaction and more dependent on internal controls. We examined the impact of exposure to PCBs on mortality, reproductive success, and tissue hormone concentrations. Exposure to Aroclor®1254 in concentrations found in natural habitats caused higher mortality and reduced reproductive success. Additionally, tissue estrogens were significantly elevated while testosterone remined unchanged in PCB-exposed snails. Given the importance of hermaphroditic freshwater gastropods in ecosystems, worldwide population decline, and ubiquity of PCBs, identifying the impact of exposure informs our ability to combat population loss.
Journal Article
Snow leopard phylogeography and population structure supports two global populations with single refugial origin
Snow leopards (Panthera uncia) inhabit the mountainous regions of High Asia, which experienced serial glacial contraction and expansion during climatic cycles of the Pleistocene. The corresponding impacts of glacial vicariance may have alternately promoted or constrained genetic differentiation to shape the distribution of genetic lineages and population structure. We studied snow leopard phylogeography across High Asia by examining range-wide historical and contemporary genetic structure with mitochondrial DNA and microsatellite markers. We genotyped 182 individuals from across snow leopard range and sequenced portions of the mitogenome in a spatially stratified subset of 80 individuals to infer historical biogeographic and contemporary patterns of genetic diversity. We observed a lack of phylogeographic structure, and analyses suggested a single refugial origin for all sampled populations. Molecular data provided tentative evidence of a hypothesized glacial refugia in the Tian Shan-Pamir-Hindu Kush-Karakoram mountain ranges, and detected mixed signatures of population expansion. Concordant assessments of microsatellite data indicated two global genetic populations, though we detected geographic differences between historical and contemporary population structure and connectivity inferred from mitochondrial and microsatellite data, respectively. Using the largest sample size and geographic coverage to date, we demonstrate novel information on the phylogeographic history of snow leopards, and corroborate existing interpretations of snow leopard connectivity and genetic structure. We recommend that conservation efforts incorporate genetic data to define and protect meaningful conservation units and their underlying genetic diversity, and to maintain the snow leopard’s adaptive potential and continued resilience to environmental changes.
Journal Article
Investigating the potential impact of trophy hunting of wild ungulates on snow leopard Panthera uncia conservation in Tajikistan
Declining availability of prey is potentially a major factor limiting snow leopard Panthera uncia populations in Tajikistan and neighbouring states. Conservation initiatives to develop community-based trophy hunting programmes for ibex Capra sibirica and argali Ovis ammon polii aim to provide financial incentives for communities to limit poaching of wild ungulates. Such programmes could help to reverse local declines in ibex and argali populations, and consequently snow leopard populations, while simultaneously improving the economic status of local people. However, in practice the desired effect may not materialize. To investigate the premise, we estimated the population density of the snow leopard, using a spatial capture–recapture model based on camera trapping in two study areas (each c. 1,000 km2) in the Tajik Pamirs: a well-managed trophy hunting concession and an otherwise similar area where grazing and poaching are unmanaged. We used distance-truncated counts to assess relative densities of wild and domestic ungulates between sites, and faecal analyses to compare the dietary habits of snow leopards. Our data were limited in scope but suggested that the density of snow leopards and the relative density of wild and domestic ungulates may have been greater in the hunting concession, where wild ungulates accounted for a greater proportion of prey items. Our results provide preliminary evidence that trophy hunting of ungulates may be a viable tool for achieving snow leopard conservation goals; however, we conclude that further investigation is necessary to adequately address the question.
Journal Article
Modelling potential habitat for snow leopards
The snow leopard Panthera uncia is an elusive species inhabiting some of the most remote and inaccessible tracts of Central and South Asia. It is difficult to determine its distribution and density pattern, which are crucial for developing conservation strategies. Several techniques for species detection combining camera traps with remote sensing and geographic information systems have been developed to model the habitat of such cryptic and low-density species in challenging terrains. Utilising presence-only data from camera traps and direct observations, alongside six environmental variables (elevation, aspect, ruggedness, distance to water, land cover, and prey habitat suitability), we assessed snow leopard habitat suitability across Ladakh in northern India. This is the first study to model snow leopard distribution both in India and utilising direct observation data. Results suggested that elevation and ruggedness are the two most influential environmental variables for snow leopard habitat suitability, with highly suitable habitat having an elevation range of 2,800 m to 4,600 m and ruggedness of 450 m to 1,800 m. Our habitat suitability map estimated approximately 12% of Ladakh's geographical area (c. 90,000 km.sup.2) as highly suitable and 18% as medium suitability. We found that 62.5% of recorded livestock depredation along with over half of all livestock corrals (54%) and homestays (58%) occurred within highly suitable snow leopard habitat. Our habitat suitability model can be used to assist in allocation of conservation resources by targeting construction of livestock corrals to areas of high habitat suitability and promoting ecotourism programs in villages in highly suitable snow leopard habitat.
Journal Article
Role of Tibetan Buddhist Monasteries in Snow Leopard Conservation
The snow leopard (Panthera uncia) inhabits the rugged mountains in 12 countries of Central Asia, including the Tibetan Plateau. Due to poaching, decreased abundance of prey, and habitat degradation, it was listed as endangered by the International Union for Conservation of Nature in 1972. Current conservation strategies, including nature reserves and incentive programs, have limited capacities to protect snow leopards. We investigated the role of Tibetan Buddhist monasteries in snow leopard conservation in the Sanjiangyuan region in China's Qinghai Province on the Tibetan Plateau. From 2009 to 2011, we systematically surveyed snow leopards in the Sanjiangyuan region. We used the MaxEnt model to determine the relation of their presence to environmental variables (e.g., elevation, ruggedness) and to predict snow leopard distribution. Model results showed 89,602 km² of snow leopard habitat in the Sanjiangyuan region, of which 7674 km² lay within Sanjiangyuan Nature Reserve's core zones. We analyzed the spatial relation between snow leopard habitat and Buddhist monasteries and found that 46% of monasteries were located in snow leopard habitat and 90% were within 5 km of snow leopard habitat. The 336 monasteries in the Sanjiangyuan region could protect more snow leopard habitat (8342 km²) through social norms and active patrols than the nature reserve's core zones. We conducted 144 household interviews to identify local herders’ attitudes and behavior toward snow leopards and other wildlife. Most local herders claimed that they did not kill wildlife, and 42% said they did not kill wildlife because it was a sin in Buddhism. Our results indicate monasteries play an important role in snow leopard conservation. Monastery‐based snow leopard conservation could be extended to other Tibetan Buddhist regions that in total would encompass about 80% of the global range of snow leopards. Papel de los Monasterios Budistas Tibetanos en la Conservación del Leopardo de las Nieves
Journal Article
Phonotactic Behavior of Male Field Crickets (Gryllus texensis) in Response to Acoustic Calls From Conspecific Males
We studied male phonotactic behaviors elicited by acoustic cues that simulate conspecific male songs in the field cricket, Gryllus texensis. Males exhibited significant positive phonotaxis in response to the simulated song stimuli, but showed no such response to atypical song stimuli. We found no significant relationship between males’ own calling behavior and their phonotactic responses to the stimuli. Analyses indicated that larger males exhibited greater phonotactic responses, which may indicate a greater tendency to engage in aggressive interactions if size is an indicator of fighting ability. Male phonotactic responses were significantly weaker than those exhibited by females, and adult males did not exhibit stronger responses with increasing age as has been documented for females. Observed sex differences in the strengths of phonotactic responses may reflect differences in the fitness-payoffs of responding. That is, females are under strong selection pressure to respond to male songs and subsequently mate. In contrast, males responding to acoustic signals from other males need not precisely locate the signaler but would likely move to areas where females are likely to be found. Alternatively, males might benefit from avoiding areas with calling males and establishing their own calling stations away from competing males.
Journal Article