The biological subfamily Bovinae includes a diverse group of about 24 medium-sized to large ungulates, including domestic cattle, bison, the Water Buffalo, the Yak, and the four-horned and spiral-horned antelopes. The evolutionary relationship between the members of the group is obscure, and their classification into loose tribes rather than formal sub-groups reflects this uncertainty.
The Boselaphini or four-hormed antelope tribe are the last survivors of a form very similar to that of the ancestors of the entire subfamily. Both species have relatively primitive anatomical and behavioural characteristics and the females have no horns. They are native to the rapidly diminishing forests of India, and tend to avoid open plains. The Ningai has been introduced into southern Texas where a population of a little under 10,000 animals provides some long-term insurance for its survival.
The Bovini tribe is made up of large to very large grazers, including large animals of great economic significance to humans in Domestic Cattle, Water Buffalo, and the Yak, as well as smaller Asian relatives, and large free-roaming bovids in the African Buffalo and the American Bison.
Where the Boselaphini and Boselaphini are mostly Asian, members of the Strepsicerotini tribe, the spiral-horned antelopes, are found only in Africa. This group tends to large size, a lighter build, longer necks and considerable sexual dimorphism. Seven of the 9 species are of conservation concern, being classified as lower-risk, conservation dependant, the remaining two, the Common Eland and the Giant Eland are secure.