Largest genus of deer

The largest deer genus is Muntiacus, housing the muntjacs or barking deer, which is generally deemed to contain 12 species, although a few researchers recognize as many as 16. The additional four were subspecies of the Javan muntjac M. muntjak elevated by these researchers to full species in their own right. Muntjacs are native to Asia, but some species have been introduced elsewhere in the world, including the UK, where they have generally thrived and become well-established naturalised species.

Certain researchers have split the five recognized species of American brocket deer (genus Mazama) into a number of additional species, resulting in as many as 23 species having been listed, but most researchers continue to recognize only the original five. A comparable situation has occurred with the red deer and wapiti (genus Cervus), most commonly deemed to contain just four species, but with as many as 17 recognized by certain "splitter" taxonomists.