The Critically Endangered Père David's deer Elaphurus davidianu became extinct in the wild in China in about 1900, and the only surviving animals were held in captivity at Woburn Abbey in the UK. During 1985–1987, individuals were returned to China, and subsequent growth of the captive population in enclosures at Dafeng Reserve necessitated a trial release of a small group of deer as a prelude to further releases. Seven individuals were released into the unfenced coastal region of the Dafeng Reserve in 1998. Behaviour, daily activity rhythm, habitat selection, activity range and body condition were recorded for six months after release. The deer exhibited initial changes in behaviour, but returned to their pre-release patterns about four weeks after release, and by six weeks after release their body condition had improved compared to their previous condition in captivity. They left the Reserve and began to forage on farmland, causing conflict with local people. Further releases should be into areas with either a natural or artificial boundary in order to avoid unmanageable levels of conflict between the needs of the deer and those of farmers.