Climate change may improve the habitat suitability and connectivity of sika deer ( Cervus nippon ) in the Shennongjia area of China

In order to effectively conserve a species and manage its population, it is critical to understand the impact of climate change on habitat quality and connectivity. The sika deer (Cervus nippon) is a ungulate species endemic to East Asia and listed as a Category I State Key Protected Wild Animals under Chinese law. The C. nippon population was established in the Shennongjia area 30 years ago, and there is an urgent need to analyse the impact of environmental change on habitat quality. In this study, we compared suitable habitats and habitat connectivity of C. nippon in the Shennongjia area by utilizing an ecological niche model that integrated a set of environmental factors combined with a cost-distance approach for both the present time as well as in the future. The most encouraging findings were that the suitable habitat for C. nippon may be obviously enlarged and its habitat connectivity obviously improved under climate change. The suitable habitat of C. nippon in the Shennongjia area is limited at present; however, it is possible that the total area and number of suitable habitat patches can increase twenty- to thirty-fold and quadruple to sextuple, respectively, in the future (2050-2070). We detected a clear trend of suitable future habitat expansion into the northeast. The number of interpatch least-cost paths may dramatically increase (up to six to twelve times higher), and the lengths of least-cost paths and movement costs for the deer may decrease by half. Based on these results, several conservation recommendations have been suggested. Our study provides a valuable reference for protective actions that can be taken to conserve C. nippon in the Shennongjia area and can serve as a template for establishing conservation strategies for other species.