Studies have been carried out on the behaviour, ecology and reproduction of Père David’s Deer in Beijing since 1985, in Dafeng since 1986, and in Shishou since 2001. This species lives in low-lying grasslands and reed beds, often in seasonally flooded areas such as the lower Yangtze River valley and coastal marshes. It eats grass, reeds and leaves of bushes, can swim well, and spend long periods in water. It lives in single sex ormaternal herds. Animals reach maturity during second year. Gestation is 270-300 days. One, rarely two young are born. These are weaned in 10-11 months. Adults live up to 18 years. Data from the Dafeng Reserve suggests that female E. davidianus establish a home range of approximately 1 km² (Hu and Jiang 2002).

This species is endemic to China. Père David’s Deer has been recovered from the brink of extinction and has become a classic example of how to rescue a highly threatened species (Ebenehard 1995). In the mid 1980s, Père David’s Deer was re-introduced into captive facilities in China, and populations established first in Beijing and then in Dafeng, Shishou and Yuanyang.

Fossils of Elaphurus bifurcatus, E. chinanensis chia, E. lantianensis have been excavated from the region east of Xi’an and south of Harbin. The modern species of Elaphurus, Père David’s Deer (Milu in Chinese) evolved in the Pliocene period of the Tertiary, according to fossils excavated in southern Japan. During the Pleistocene period, it was known from Manchuria (Hofmann 2007). During the Holocene, P. davidianus was restricted to swamps and wetlands in the region south of 43°N and east of 110°E in mainland China (Cao 1993, Zhou 2007). However, the distribution of P. davidianus shrank and its population declined due to hunting and land reclamation in the swamp areas as human population expanded (Jiang and Li 1999). P. davidianus is believed to have been largely extinct in the wild 1500 years before the last head was decimated by the late 19th century during the Boxer Rebellion in Beijing.

During the Qing Dynasty (1616-1911), the Nanyuang Royal Hunting Garden contained a herd of P. davidianus in its 200 km² hunting ground. This hunting garden in the southern suburbs of Beijing was predominantly a wetland, consisting of swamps, ponds and lakes crossed by the Yongding River. The area had been sealed off from the outside world since the Yuan Dynasty (1205-1368) as a royal garden. The French missionary Père Armand David “discovered” P. davidianus in the Nanyuan Royal Hunting Garden in 1864. Realizing that the deer was an unknown species to the West, he persuaded the wardens to give him hinds and skeletons of an adult male, an adult female and a young male, and sent them to Paris in 1866, where the species was named Père David’s deer by Milne-Edwards. In 1895, the surrounding wall of the Nanyuan Hunting Garden was destroyed by a heavy flood of the Yongding River, and most of the Père David’s Deer escaped and were hunted. Only 20-30 animals survived in the garden. Then in 1900, during the Boxer Rebellion, the garden was occupied by troops and the remaining deer were shot and eaten.

However, before the demise of the royal herd of Père David’s Deer in the Nanyuan Royal Hunting Garden in 1900, the deer had been introduced into private deer collections in the United Kingdom, Belgium, France and Germany. During the first decade of the 20th century, the 11th Duke of Bedford in the United Kingdom gathered the last 18 Père David’s Deer in the world to form a breeding herd at the Woburn Abbey Estate, England. Only 11 of these deer were capable of reproducing (Bedford, 1951-52). Nevertheless, the heavily inbred Père David’s Deer safely passed though the genetic bottleneck of inbreeding and adopted the vast open parkland of an English country estate (Jones et al. 1983).

The captive population started to increase (though with a setback during the First World War due to food shortage), and since the Second World War, the animals started to be spread through captive facilities worldwide, with the first captive animals being sent back to Beijing Zoo in 1956.

It is listed on the Chinese Red List as Extinct in the Wild, and on the China Key List - I.

Recommended conservation action includes:
1. Establish additional populations when and where appropriate, with the aim of re-establishing a genuinely wild, free-ranging population.
2. Conduct surveys of the four free-living sub-populations in Hubei and Hunan provinces to assess their long-term viability.
3. Establish a genetic management programme of all populations in China.
4. Develop conservation education programmes to raise conservation awareness among the local people and general public.

Following a trial release of this species in the Dafeng Reserve, China, Hu and Jiang (2002) concluded that future releases will necessitate either natural or artificial boundaries to alleviate conflict between introduced E. davidianus and farmers, on whose land the deer are likely to stray. These authors suggest a reintroduction model based on that of Oryx leucoryx in Oman (Stanley Price 1989).