Identification of Release Habitat of Captive-bred Mammals Demonstrated for Giant Panda in Sichuan Province, China

Two thirds of the giant panda population in the Sichuan Province of China is at risk of extinction due to habitat fragmentation. Connectivity constraints prevent spontaneous re-population of remaining fragments of their historical habitat. On the other hand, the increasing number of captive-bred giant panda makes release into the wild feasible. A comprehensive approach for the identification of potential release habitat and the number of giant panda required for rewilding is demonstrated. The extent of the uninhabited giant panda habitat in 2013 and in 2060 was established by using the MaxEnt species distribution algorithm, published occurrence points (n = 1014) and a broad range of landscape variables namely, climatic, terrain, soil, vegetation and human impact, including mines and roads. We used AUC, SD, kappa, CCI, NMI, the odds ratio, TSS, bootstrap replicates and an alternative preprocessing of predictor variables to validate our model. A least cost path (LCP) between habitat fragments was calculated to identify dispersal corridors required for avoidance of inbreeding. Well-connected, uninhabited habitat patches and their number of home ranges were identified. Considering the net reproduction rate of giant panda, we calculated the number of giant panda to be released annually over a 25 or 50 year period, to fully occupy the available home ranges. We identified 6.900 km(2) well-connected, uninhabited habitat allowing for the annual release of 45-89 or 10-20 captive-bred giant panda for a 25 or 50 year release project. We suggest that our approach may be used for the reintroduction of other large solitary terrestrial mammals.

Automated summary

The study highlighted the risk of extinction for two thirds of the giant panda population in Sichuan Province, China, due to habitat fragmentation. It also demonstrated the feasibility of reintroducing captive-bred pandas into the wild. By identifying potential release habitat and calculating the number of pandas needed for rewilding, a comprehensive approach was provided for the conservation of giant panda populations.