Johansson, O., Samelius, G., Wikberg, E, Chapron, G., Mishra, C., Low, M. (2020). Identification errors in camera- trap studies result in systematic population overestimation. Scientific Reports, 10(6393), 1–10.
Abstract: Reliable assessments of animal abundance are key for successful conservation of endangered species. For elusive animals with individually-unique markings, camera-trap surveys are a benchmark standard for estimating local and global population abundance. Central to the reliability of resulting abundance estimates is the assumption that individuals are accurately identified from photographic captures. To quantify the risk of individual misidentification and its impact on population abundance estimates we performed an experiment under controlled conditions in which 16 captive snow leopards (Panthera uncia) were camera-trapped on 40 occasions and eight observers independently identified individuals and recaptures. Observers misclassified 12.5% of all capture occasions, resulting in systematically inflated population abundance estimates on average by one third (mean ± SD = 35 ± 21%). Our results show that identifying individually-unique individuals from camera-trap photos may not be as reliable as previously believed, implying that elusive and endangered species could be less abundant than current estimates indicate.
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Atzeni, L., Cushman, S. A., Bai, D., Wang, J., Chen, P., Shi,
K., Riordan, P. (2020). Meta-replication, sampling bias, and multi-scale model selection:
A case study on snow leopard (Panthera uncia) in western China. Ecology and Evolution, , 1–27.
Abstract: Replicated multiple scale species distribution models (SDMs)
have become increasingly important to identify the correct variables
determining species distribution and their influences on ecological
responses. This study explores multi-scale habitat relationships of the
snow leopard (Panthera uncia) in two study areas on the Qinghai–Tibetan
Plateau of western China. Our primary objectives were to evaluate the
degree to which snow leopard habitat relationships, expressed by
predictors, scales of response, and magnitude of effects, were
consistent across study areas or locally landcape-specific. We coupled
univariate scale optimization and the maximum entropy algorithm to
produce multivariate SDMs, inferring the relative suitability for the
species by ensembling top performing models. We optimized the SDMs based
on average omission rate across the top models and ensembles’ overlap
with a simulated reference model. Comparison of SDMs in the two study
areas highlighted landscape-specific responses to limiting factors.
These were dependent on the effects of the hydrological network,
anthropogenic features, topographic complexity, and the heterogeneity of
the landcover patch mosaic. Overall, even accounting for specific local
differences, we found general landscape attributes associated with snow
leopard ecological requirements, consisting of a positive association
with uplands and ridges, aggregated low-contrast landscapes, and large
extents of grassy and herbaceous vegetation. As a means to evaluate the
performance of two bias correction methods, we explored their effects on
three datasets showing a range of bias intensities. The performance of
corrections depends on the bias intensity; however, density kernels
offered a reliable correction strategy under all circumstances. This
study reveals the multi-scale response of snow leopards to environmental
attributes and confirms the role of meta-replicated study designs for
the identification of spatially varying limiting factors. Furthermore,
this study makes important contributions to the ongoing discussion about
the best approaches for sampling bias correction.
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Mallon, D. (1984). The snow leopard in Ladakh. International Pedigree Book of Snow Leopards, 4, 23–37.
Abstract: Reports on 1 summer survey and four winter surveys covering some 3100 km in Ladakh, India. Reports on snow leopard sign commonly found, distribution, prey, attacks on livestock and peoples reaction, mortality factors and conservation status. Suggest recomendations for preventing unnecessary killing of snow leopards and estimates population of 100 to 200 snow leopards in Ladakh
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Koshkarev, E. P. (1984). Characteristics of snow leopard (Uncia uncia) movements in the Tien Shan. International Pedigree Book of Snow Leopards, 4, 15–21.
Abstract: Reports on a 3 yr winter study of snow leopard movements and activity, based on following tracks in the snow in Tien Shan Mountains of USSR. Travel route preference is examined with regard to snow and terrain characteristics, and prey abundance. Snow leopard kills of ibex and hare are noted
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Blomqvist, L. (1984). Conservation Measurements taken for the Captive Snow Leopard, Panthera uncia, Population and a Report of Fluctuations in Stock in 1983. Int.Ped Book of Snow Leopards, 4, 55–71.
Abstract: Reports on conservation measures over the past 10 years. Notes current snow leopard exchange programs between zoos in the US and USSR and Europe. Describes status and reproductive success of the captive snow leopard population, list animals currently in captivity.
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Fox, J. L. (1974). An ecological survey of the proposed Langtang National Park.
Abstract: Reports probable sighn of snow leopard at two high elevation points in the Langtang National Park
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Rowell, G. (1983). China's Wildlife Lament. International Wildlife, 13(6), 4–11.
Abstract: Reports sightings of snow leopard in Qinghai Province. One freshly killed; a 15 yuan bounty exists on snow leopards
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McVittie, R. (1978). Nursing behavior of snow leopard cubs. Applied-Animal-Ethology, 4(2), 159–168.
Abstract: Reports that a preliminary project on nursing behavior in 3 young snow leopards revealed 2 phases in suckling pattern: nonnutritive and nutritive. The latter was distinguished by stereotypic rhythmical movements of the ears associated with swallowing. The cubs also demonstrated a teat preference, but the adaptive significance of such preferences and the accompanying agonistic behavior were unclear. (27 ref) (PsycINFO Database Record (c) 2000 APA, all rights reserved)(unassigned)
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Osborne, B. C., Mallon, D. P., & Fraser, S. J. R. (1983). Ladkh, threatened stronghold of rare Himalayan mammals. Oryx, 17, 182–189.
Abstract: Reports the results of seven visits to Ladakh over past five years. The snow leopard occurs throughout Ladakh but is not common. Livestock are often taken in winter. At least five snow leopards were shot in the Suru Valley over the past five years. The pelt is worth about $350 in Srinagar.
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Alibekov L.A. (1978). Fauna.
Abstract: Represented is fauna of big salt-marsh valleys and pre-Kyzylkum area, a tier of low desert foothill valleys, tiers of lowland ridges, deeply cut hillside midlands, and cold highlands of the watershed ridge-top tier in the Jizak region of Uzbekistan. The highest tier of the Jizak region, a habitat of snow leopard, Menzbier's marmot, Siberian ibex, sometimes wild Tajik sheep coming from the East, bear ascending from lower elevations, and wolf in summer, has the most adverse living conditions. Central Asia argali and stone marten inhabit in central part of the North Nurata ridge.
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