Deer escape flooding in China and revive a species

In China, David’s deer, also known as milu, began recovering their population after a flood unexpectedly allowed them to leave a protected reserve.

In the 20th century, conservation efforts often involved placing rare animals in zoos and reserves to prevent extinction. However, milu deer demonstrated a different path to recovery, thriving only when they returned to the wild.

Once common in the Yangtze River basin, the deer disappeared from Chinese wildlife by the early 20th century due to habitat loss, hunting, and climate change. Researchers with the Chinese Academy of Sciences’ Institute of Zoology began reintroducing the deer to China in 1985, bringing animals from England to a park in Beijing. In 1991, authorities established the Hubei Shishou Milu National Nature Reserve on an island in the Yangtze River, and 64 deer were moved there by 1994.

A major flood in May 1998 proved to be a turning point when rising waters allowed 36 deer to escape the reserve and swim across the Yangtze. Researchers found they could not return the deer to the reserve, as the animals had moved into wetland areas. This escape initiated the natural growth of the deer population outside of the protected area, allowing them to breed and spread beyond the reserve's boundaries.

By the end of 2009, the number of wild milu deer, including their offspring, exceeded 500. The population later declined due to a disease outbreak in early 2010, but by the end of 2012, approximately 300 wild milu deer lived in several isolated groups near Dongting Lake.