Concept
The sika deer (Cervus nippon), also known as the Northern spotted deer or the Japanese deer, is a species of deer native to much of East Asia and introduced to other parts of the world. Previously found from northern Vietnam in the south to the Russian Far East in the north, it is now uncommon except in Japan, where the species is overabundant. Its name comes from 鹿, the Japanese word for "deer". In Japan, the species is known as the "Japan deer". In Chinese, it is known as . The sika deer is a member of the genus Cervus, a group of deer also known as the "true deer". Formerly, sika were grouped together in this genus with nine other species. Now, only the sika and red deer remain, the latter being divided into three separate species: European red deer, central Asian red deer, and American elk (though this remains controversial). Recent DNA evidence indicates these deer are not as closely related as previously thought, resulting in the creation of new species and genera. The genera Rucervus, Rusa, and Przewalskium are where most of the former Cervus species now belong. The ancestor of all Cervus species probably originated in central Asia and resembled sika deer. All Cervus species can crossbreed and produce hybrids in areas where they coexist (for example, introduced sika hybridize with native red deer in the Scottish Highlands, where this is a serious threat to the gene pool of the red deer population). Serious genetic pollution has occurred in many populations, especially in China, so the status of many subspecies remains unclear. The status of C. n. hortulorum is particularly uncertain and might in fact be of mixed origin, hence it is not listed here. C. n. aplodontus, northern Honshu C. n. grassianus, Shanxi, China C. n. keramae, Kerama Islands of the Ryukyu Islands, Japan C. n. kopschi, southern China C. n. mandarinus, northern and northeastern China C. n. mantchuricus, northeastern China, Korea, and Russian Far East C. n. nippon, southern Honshu, Shikoku, and Kyushu C. n. pseudaxis, northern Vietnam C. n.
