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bioRxiv · 10.1101/2022.08.03.502614

The cost of sympatry: spatio-temporal patterns in leopard dietary and physiological responses to tiger competition in Rajaji Tiger Reserve, India

Patel, S. K.·Ruhela, S.·Biswas, S.·Bhatt, S.·Pandav, B.·Mondol, S.
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Abstract

1.O_LIApex predators have critical roles in maintaining the structure of ecosystem functioning by controlling intraguild subordinate populations. Such dominant-subordinate interactions involve agonistic interactions including direct (death/displacement) or indirect (physiological and/or health implications) impacts on the subordinates. As these indirect effects are often mediated through physiological processes, it is important to quantify such responses for better understanding of population parameters. C_LIO_LIWe used a well-known sympatric large carnivore intraguild system involving tiger (Panthera tigris) and leopard (Panthera pardus) to understand the dietary and physiological responses under a spatio-temporal gradient of tiger competition pressures in Rajaji Tiger Reserve (RTR), a major source tiger population of the western Terai-Arc Landscape, India between 2015-2020. The park provided a natural experimental set-up for tiger competition with the eastern part (ERTR) having high tiger density and the western (WRTR) part with functionally no competition from tigers. C_LIO_LIWe conducted systematic faecal sampling in the winters of 2015 and 2020 from ERTR and WRTR to assess diet and physiological measures. Analyses of leopard-confirmed faeces suggest a dietary-niche separation as a consequence of tiger competition. In 2020, we found increased occurrence of large-bodied prey species without tiger competition in WRTR. Physiological measures followed the dietary responses where leopards with large-sized prey in diet showed higher fT3M and lower fGCM measures in WRTR. In contrast, ERTR leopards showed lower levels of fT3M as well as fGCM in 2020, possibly due to intense competition from tigers. Overall, these pattens strongly indicate a physiological cost of sympatry where competition with dominant tigers resulted in elevated nutritional stress. C_LIO_LIThe combination of the natural habitat providing unique experimental setup, spatio-temporal sampling strategy and multidisciplinary approaches provide critical conservation perspectives for leopards, particularly in the context of recent increase in tiger numbers across India. We recommend expansion of leopard monitoring and population estimation efforts to buffers, developing appropriate plans for human-leopard conflict mitigation and intensive efforts to understand leopard population dynamics patterns to ensure their persistence during the ongoing Anthropocene. C_LI

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Patel, S. K., Ruhela, S., Biswas, S., Bhatt, S., Pandav, B., Mondol, S.. 2022-08-05. The cost of sympatry: spatio-temporal patterns in leopard dietary and physiological responses to tiger competition in Rajaji Tiger Reserve, India. https://doi.org/10.1101/2022.08.03.502614

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