Père David's deer

This marsh-loving deer vanished from China around 1900 and survived only because the Duke of Bedford gathered Europe's last 18 captive animals into one herd at Woburn Abbey in England. Every Père David's deer alive today descends from that private park. Deer went home to China from 1985, first from Woburn to Beijing, and in 1986 another 39 from British zoos founded the herd at Dafeng in Jiangsu Province, which has grown past 8,200. It is a spectacular rebound in numbers, but every animal traces back to a handful of founders, and that narrow genetic base is a lasting concern for the species.