The Vietnamese sika deer is a subspecies thought to have been extinct in the wild since the 1990s. It once lived in the tropical forests and wetlands of central and southern Vietnam. It fell victim to heavy hunting, together with the huge destruction of its home during the decades of war that tore the country apart. Chemical weedkillers (such as Agent Orange) wiped out much of its environment for good. The few survivors now live only in captivity, in zoos and specialist breeding centres. International programmes are working to keep a healthy captive population, with enough genetic variety, so that one day it might be returned to restored protected areas.