Dispersal of reintroduced Chinese water deer after release in Nanhui East Shoal Wildlife Sanctuary of Shanghai, China

Abstract As a native species in history, Chinese water deer were reintroduced to Shanghai in 2006 and were released into the wild, at Nanhui East Shoal Wildlife Sanctuary, in 2010. In order to study the dispersal, we used radio telemetry to track 12 released deer’s movements. The research suggests that all the bucks showed clear dispersal behaviour in the initial period, and their dispersal occurred earlier and lasted longer than that of the does. Most bucks’ dispersing movement occurred from the third day to the fifth day after release, and the dispersing does’ movement occurred from the eighth to the ninth day. The first dispersal of the bucks lasted for 4–5 days, while this was only 1–2 days for the does. The mean dispersal distance for the bucks was 623 m in the initial period of relocation, and that of the does was significantly smaller. The dispersal distance for sub-adults was also considerably smaller than that of the adults. Reed wetland was the main habitat the deer liked to select. After the initial period, the mean dispersal distance was 857 m and bucks still dispersed significantly farther than does did. Most surviving individuals displayed a new dispersal during early December, but the adult does showed a tendency of retraction from the following January. Unfamiliarity with new environments might explain why the deer did not immediately disperse after release. After becoming familiar with food distribution and shelter conditions, they dispersed further in order to avoid predation risk. In order to improve the survival rate of reintroduced deer, we suggest releasing the adult individuals of robust physique into the wild in future programmes, and more attention should be paid to the initial 9 days after releasing the species. Increasing the local experience of the captive-born animals and helping them become familiar with the new wild habitat will improve the survival rate in future reintroductions.