Mobaraki, A., M. Erfani, E. Abtin, J. C. Brito, W. C. Tan, T. Ziegler & D. Rödder

Last chance to see? Iran and India as strongholds for the Mugger Crocodile (Crocodylus palustris). pp. 327-335.

Abstract. Justified predictions of future changes in species distributions are necessary for defining adequate conservation plans over space and time. The Marsh or Mugger Crocodile (Crocodylus palustris) is native to freshwater habitats of the Indian subcontinent and in southeastern Iran. Habitat loss is currently the most important threat to crocodile dispersal and persistence, and climate change will likely exert increasing pressure on populations. This study used ecological niche modelling (maximum entropy) to predict the current distribution of this species and project it to future climatic conditions. For this purpose, 380 occurrence records were used for model computation and environmental data were obtained from Worldclim 2.0. Averages of eight global circulation model outputs, assuming four IPCC6 per story lines in 2081–2100, were used as future ensembles. Furthermore, future possible anthropogenic pressure was quantified using economic growth models. Temperature Annual Range was the climatic variable with the highest contribution to the modelling. Presently, most potential suitable habitats are located in Sri Lanka, in the southeastern peninsular of India, the tropical moist forest along the west coast of India, the border region between Nepal and India, and the south coasts of Iran and Pakistan. In the future, these suitable habitats are predicted to be further fragmented and to shift farther inland. Additional threats may arise from increased human/crocodile conflicts due to human population growth. Conservation should therefore focus on those areas that remain climatically comparatively stable with a low potential of human/crocodile conflicts. Key areas are located in the northern parts of India and at the westernmost range limits of this species in Iran.

Key words. Crocodylidae, biodiversity, global warming, habitat suitability, spatial conservation planning, species distribution modelling.