The Key Deer is an endangered

Endangered species

An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...

 deer

Deer

Deer are the ruminant mammals forming the family Cervidae. Species in the Cervidae family include white-tailed deer, elk, moose, red deer, reindeer, fallow deer, roe deer and chital. Male deer of all species and female reindeer grow and shed new antlers each year...

 that lives only in the Florida Keys

Florida Keys

The Florida Keys are a coral archipelago in southeast United States. They begin at the southeastern tip of the Florida peninsula, about south of Miami, and extend in a gentle arc south-southwest and then westward to Key West, the westernmost of the inhabited islands, and on to the uninhabited Dry...

. It is a subspecies of the White-tailed deer

White-tailed Deer

The white-tailed deer , also known as the Virginia deer or simply as the whitetail, is a medium-sized deer native to the United States , Canada, Mexico, Central America, and South America as far south as Peru...

 (O. virginianus).
This deer can be recognized by its characteristic size, smaller than all other White-tailed deer. Adult males (known as bucks) usually weigh 25–34 kg (55.1–75 lb) and stand about 76 centimetres (29.9 in) tall at the shoulder. Adult females (does) usually weigh between 20–29 kg (44.1–63.9 lb) and have an average height of 66 centimetres (26 in) at the shoulders.