All 14,000 milu deer in the world descend from eleven individuals. At the beginning of the 20th century, these eleven lived not in China but in Woburn Abbey, England. China lost the species in 1900, but an English nobleman prevented its complete extinction. From this founding group in Bedfordshire, more than 14,000 animals emerged in four decades, today distributed across multiple reserves in China.
The End in the Imperial Park and the Ark in England
The last milu deer lived in the Imperial Hunting Park south of Beijing, isolated from the outside world as a symbol of imperial prestige. In 1895, a severe flood broke the park walls and killed most of the herd. The survivors died during the Boxer Rebellion in 1900 when troops invaded the park. The species was completely extinct in China.
Herbrand Russell, the 11th Duke of Bedford, recognized the danger of complete extinction between 1894 and 1904. He gathered milu deer scattered across European zoos and brought them to his estate at Woburn Abbey in Bedfordshire. Of the 18 animals he assembled, 11 ultimately contributed to the species' continuation. All 14,000 milu deer alive today are descendants of these eleven individuals.
39 Deer and a New Home in Jiangsu
In 1985, the Marquess of Tavistock, owner of Woburn Abbey, gave 22 milu deer to China as a gift. Of these 22, 20 went to Nanhaizi Park south of Beijing, the former Imperial Hunting Park. In 1986, 39 animals from several British zoos were released in the Dafeng National Reserve in Jiangsu Province. Dafeng lies in a coastal wetland on the Yellow Sea coast and resembles the species' historical habitat: flat marshes, reed beds, and slow rivers.
The result after forty years: the Dafeng Reserve now hosts more than 8,500 milu deer, of which 3,673 live completely free without enclosures. Across China, Xinhua news agency reports, the population exceeds 14,000 animals distributed across multiple reserves and breeding centers. The total population has grown 200-fold since the 1985 return, equivalent to an average annual growth rate of about 13 percent.
Scientific publications emphasize that the Dafeng Reserve succeeded in returning a species that survived only in zoo captivity to a largely self-sustaining wildlife ecosystem. Wild populations that reproduce without human feeding or constant veterinary intervention are the true goal of any rewilding effort.
In Comparison: What Other Species Have Achieved
The milu deer is not alone among animal comebacks in recent decades. The European bison was extinct in the wild by 1927 after the last wisent was killed in the Caucasus. Its rescue began in 1923 when zoo biologists initiated a coordinated breeding program for surviving animals in captivity. By the end of 2024, the European Bison Studbook lists 12,209 animals worldwide, with 9,762 living free in the wild. Poland and Russia each host around 3,000 individuals, the largest populations.
The Iberian lynx numbered just 62 breeding individuals in 2001. By December 2024, 2,401 animals inhabited the Iberian Peninsula, with 2,047 in Spain and 354 in Portugal. This represents a 39-fold increase in 23 years. In June 2024, the International Union for Conservation of Nature downlisted the species from "critically endangered" to "endangered," a step rarely taken in the Red List.
What all three species share: their recovery did not begin with a natural phenomenon but with a political decision. In China, it was the 1985 decision to accept a diplomatic gift and reserve wetlands for a handful of unknown deer. In Spain, the funding of a lynx breeding program through EU LIFE grants starting in 2002. In Poland, the 1923 decision to maintain a last breeding population in state zoos.
The Inbreeding Problem: All 14,000 Descend from Eleven
Behind the success numbers lies a biological threat that Chinese scientists do not hide. Because all milu deer worldwide originate from a genetic pool based on eleven animals, the population shows typical inbreeding traits: elevated miscarriage rates, shorter lifespans, and increased disease susceptibility. Chinese biologists studying milu population dynamics identify genetic narrowness as a central open question in conservation.
The Chinese government has responded. Asia's largest milu genetic bank is now being built in the Dafeng Reserve. The goal is systematic preservation of genetic material for future genetic diversification. Cooperation with zoological institutions will bring genomic tools already proven in European bison. An animal whose numbers register as success is not yet biologically secured. A population without genetic diversity is more vulnerable to new pathogens and climate extremes than one descended from hundreds of independent lineages.
The milu deer has completed the first stage of its return. From zero free-living animals in China to 14,000 in four decades is more than symbolic politics. The second stage, building genetic resilience, has just begun.