Browsing by Author "Weiskopf, Sarah"
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Item Assessing mammal biodiversity in forest fragments of the Asian tropics(University of Delaware, 2016) Weiskopf, SarahDeforestation of tropical rainforests is one of the greatest current threats to biodiversity. Asian mammals have been particularly threatened by land use change, yet we lack basic information about many species. This lack of information is a major obstacle to effective conservation, and is driven in part by the high cost and effort required to survey tropical mammals. In the first chapter of this thesis, we used camera traps to investigate the mammalian use of five small forest fragments outside Bukit Barisan Selatan National Park in Sumatra, Indonesia, and compared it to camera trapping which was carried out inside the national park. We found that a significant number of forest species were utilizing the fragments, including endangered species such as the Sunda pangolin (Manis javanica) and the Sumatran tiger (Panthera tigris sumatrae). The high level of biodiversity found in these fragments suggests that these areas may be of conservation importance, and may increase connectivity across the landscape. In the second chapter of this thesis, we addressed the difficulties of tropical mammal surveys by examining a novel survey technique: genetic sequencing of leech blood meals. We used Sanger sequencing of the 16s rRNA gene to identify recent mammal host species of leeches collected from four forest patches in northeast Bangladesh. We then compared these data to camera trap data obtained from the same locations. We identified a greater number of species in the camera traps than in the leeches; however, leeches may be able to provide a more precise picture of biodiversity in the study area. After comparing the effort, cost, and power associated with each method, both methods have pros and cons. Used together, these methods may provide a more complete monitoring tool for mammal biodiversity in tropical rainforests.Item What Are Snow Leopards Really Eating? Using Genetics to Reduce Bias in Food Habit Studies(University of Delaware, 2014-05) Weiskopf, SarahFood 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.