Impact of climate change on Asiatic black bear (Ursus thibetanus) and its autumn diet in the northern highlands of Pakistan.

Abstract

Approximately 20%-30% of plant and animal species are at risk of extinction by the end of the 21st century owing to climate change. Range shifts and range contractions in plant species will dramatically affect the distribution of animals relying on them for food and shelter. The negative impacts of climate change on forested landscapes of the northern highlands of Pakistan (NHP) could change the species composition and distribution. The Asiatic black bear (Ursus thibetanus), a forest-dwelling species, primarily depends on plants for foraging, and is assumed to be affected by climate change in NHP. Scat analyses and indigenous knowledge from Machiara National Park revealed the maximum consumption of Quercus species (natural food) and Zea mays (human grown food) by the Asiatic black bear in autumn season. We collected the occurrence data of the Asiatic black bear and its commonly used food (three Quercus spp.) in the NHP. We used the MaxEnt model to simulate current and future (in 2050 and 2070) distribution of the species under RCP4.5 (medium carbon emission scenario) and RCP8.5 (extreme carbon emission scenario). The results predict range reduction and extreme fragmentation in the habitats of all the Quercus spp. Besides, a dramatic decrease in the suitable (SH) and very highly suitable (HSH) habitats was predicted in the future. Range shift and range reduction of Quercus spp. may interrupt the denning chronology of Asiatic black bears, escalate the human-black bear conflicts and local extirpation of the species. Given the extent and magnitude of climate change, it will likely not be enough to focus solely on the conservation of the Asiatic black bear. We need more dynamic planning aiming at mitigating the effect of climate change in forested landscapes including the Quercus forests.