What Are Snow Leopards Really Eating? Using Genetics to Reduce Bias in Food Habit Studies
Date
2014-05
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Publisher
University of Delaware
Abstract
Food availability is widely recognized as a primary threat to snow leopard (Panthera uncia) populations throughout their range. Effective conservation of snow leopards therefore depends upon reliable knowledge of their food habits. Unfortunately, past food habit studies may be inherently biased by the inclusion of non-target species in fecal analysis. Differentiation between snow leopard and sympatric carnivore scat is now cost-effective and reliable using genetic tools. In this study, we leverage fecal DNA analysis to both assess and remove bias in snow leopard food habit studies. We first analyzed presumed snow leopard scats collected from Central Asia, using standard microscopy methods to identify prey species based on medullar and cuticular characteristics of guard hairs found in the scats. We then estimated food habits for each study site under the assumption that all collected feces were of snow leopard origin. We then subset the data to include only snow leopard scats, as verified through fecal DNA, allowing us to compare results and estimate bias. Fecal samples from the four study locations ranged from 21-64% snow leopard. Analyzing all collected scats overestimated the percent occurrence, biomass, and number of small mammals consumed and underestimated these measures for large ungulates in snow leopard diet. Our results show that, lacking genetic analysis of collected fecal samples, scientists likely include a large percentage of scats originating from other predators, thus altering the results of their studies. This could erroneously shift the target of conservation to more small mammals and fewer ungulates than truly required for a snow leopard population.