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Shrestha, B., Aihartza, J., Kindlmann. (2018). Diet and prey selection by snow leopards in the Nepalese Himalayas. PLoS ONE, , 1–18.
Abstract: Visual attractiveness and rarity often results in large carnivores being adopted as flagship
species for stimulating conservation awareness. Their hunting behaviour and prey selection
can affect the population dynamics of their prey, which in turn affects the population dynamics
of these large carnivores. Therefore, our understanding of their trophic ecology and foraging
strategies is important for predicting their population dynamics and consequently for
developing effective conservation programs. Here we concentrate on an endangered species
of carnivores, the snow leopard, in the Himalayas. Most previous studies on snow leopard
diet lack information on prey availability and/or did not genetically check, whether the
identification of snow leopard scats is correct, as their scats are similar to those of other
carnivores. We studied the prey of snow leopard in three Himalayan regions in Nepal
(Sagarmatha National Park (SNP), Lower Mustang (LM) and Upper Manang (UM) in the
Annapurna Conservation Area, during winter and summer in 2014�2016. We collected 268
scats along 139.3 km linear transects, of which 122 were genetically confirmed to belong to
snow leopard. Their diet was identified by comparing hairs in scats with our reference collection
of the hairs of potential prey. We determined prey availability using 32�48 camera-traps
and 4,567 trap nights. In the SNP, the most frequent prey in snow leopard faeces was the
Himalayan tahr in both winter and summer. In LM and UM, its main prey was blue sheep in
winter, but yak and goat in summer. In terms of relative biomass consumed, yak was the
main prey everywhere in both seasons. Snow leopard preferred large prey and avoided
small prey in summer but not in winter, with regional differences. It preferred domestic to
wild prey only in winter, and in SNP. Unlike most other studies carried out in the same area,
our study uses genetic methods for identifying the source of the scat. Studies solely based
on visual identification of samples may be strongly biased. Diet studies based on frequency
of occurrence of prey tend to overestimate the importance of small prey, which may be consumed
more often, but contribute less energy than large prey. However, even assessments
based on prey biomass are unlikely to be accurate as we do not know whether the actual
size of the prey consumed corresponds to the average size used to calculate the biomass
eaten. For example, large adults may be too difficult to catch and therefore mostly young animals are consumed, whose weight is much lower. We show that snow leopard consumes
a diverse range of prey, which varies both regionally and seasonally. We conclude that in
order to conserve snow leopards it is also necessary to conserve its main wild species of
prey, which will reduce the incidence of losses of livestock.
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Alexander, J. S., Gopalswamy, A. M., Shi, K., Riordan, P. (2015). Face Value: Towards Robust Estimates of Snow Leopard Densities. Plos One, .
Abstract: When densities of large carnivores fall below certain thresholds, dramatic ecological effects
can follow, leading to oversimplified ecosystems. Understanding the population status of
such species remains a major challenge as they occur in low densities and their ranges are
wide. This paper describes the use of non-invasive data collection techniques combined
with recent spatial capture-recapture methods to estimate the density of snow leopards
Panthera uncia. It also investigates the influence of environmental and human activity indicators
on their spatial distribution. A total of 60 camera traps were systematically set up during
a three-month period over a 480 km2 study area in Qilianshan National Nature Reserve,
Gansu Province, China. We recorded 76 separate snow leopard captures over 2,906 trapdays,
representing an average capture success of 2.62 captures/100 trap-days. We identified
a total number of 20 unique individuals from photographs and estimated snow leopard
density at 3.31 (SE = 1.01) individuals per 100 km2. Results of our simulation exercise indicate
that our estimates from the Spatial Capture Recapture models were not optimal to
respect to bias and precision (RMSEs for density parameters less or equal to 0.87). Our
results underline the critical challenge in achieving sufficient sample sizes of snow leopard
captures and recaptures. Possible performance improvements are discussed, principally by
optimising effective camera capture and photographic data quality.
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