Influnece of prey availability and abiotic factors on habitat utilization of mugger crocodile (Crocodylus palustris) and interactions with Fishermen in the Moyar-Bhavanisagar landscape

Abstract

Crocodilians are considered to be apex predators of freshwater ecosystems, yet little is known crocodilians often compete with fishermen over fish resources. This study aims to measure the influence of prey availability (fish biomass) and abiotic features on the habitat utilization of mugger crocodiles in the Moyar river and to quantify crocodile-caused net damages and the associated costs experienced by fishermen in the Bhavanisagar reservoir. Model selection revealed that fish biomass was the best fit model for crocodile habitat utilization, along with sandy banks (which was most preferred for basking) and wider river sections, which showed weaker model fit for habitat utilization. Questionnaire surveys involving fishermen and experimental net monitoring in the reservoir revealed that the perceived frequency of crocodile caused net damage is approximately 2.2 times higher than the observed frequency of net damage. The mean estimate of losses experienced by fishermen over a four month period in the reservoir due to crocodiles was calculated to be approximately Rs. 32,029. Nets placed closer to the bank experienced more damage by crocodiles than nets placed further from the bank. This study highlights the importance of prey availability and scientific management and monitoring of habitat for crocodile populations and provides baseline information on fishermen-crocodile conflict and can aid in informing stakeholders in implementing mitigation measures and compensation schemes.