The Sika Deer, Cervus nippon, also known as the Spotted Deer or the Japanese Deer, is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of 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...

 native to much of East Asia

East Asia

East Asia or Eastern Asia is a subregion of Asia that can be defined in either geographical or cultural terms...

 and introduced to various other parts of the world. Previously found from northern Vietnam

Vietnam

Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...

 in the south to the Russian Far East

Russian Far East

Russian Far East is a term that refers to the Russian part of the Far East, i.e., extreme east parts of Russia, between Lake Baikal in Eastern Siberia and the Pacific Ocean...

 in the north, it is now on the brink of extinction in all areas except Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, where the species is overabundant. Its name comes from , the Japanese word for "deer".
The Sika Deer is a member of the genus Cervus

Cervus

Cervus is a genus of deer that primarily are native to Eurasia, although one species occurs in northern Africa and another in North America. In addition to the species presently placed in this genus, it has included a whole range of other species now commonly placed in other genera, but some of...

, a group of deer also known as the "true deer".