Muntjacs, also known as barking deer and Mastreani deer, are small deer of the genus Muntiacus. Muntjacs are the oldest known deer, thought to have begun appearing 15–35 million years ago, with remains found in Miocene deposits in France, Germany and Poland.
The present-day species are native to South Asia and can be found in Sri Lanka, Southern China, Taiwan, Japan (Boso Peninsula and Ōshima Island), India and Indonesian islands. They are also found in the lower Himalayas and in Burma. Inhabiting tropical regions, the deer have no seasonal rut and mating can take place at any time of year; this behaviour is retained by populations introduced to temperate countries.
Reeves’s muntjac has been introduced to England, with wild deer descended from escapees from the Woburn Abbey estate around 1925. Muntjacs have expanded very rapidly, and are now present in most English counties south of the M62 motorway and have also expanded their range into Wales. The British Deer Society coordinated a survey of wild deer in the UK between 2005 and 2007, and they reported that muntjac deer had noticeably expanded their range since the previous census in 2000. It is anticipated that muntjacs may soon become the most numerous species of deer in England and may have also crossed the border into Scotland with a couple of specimens appearing in Northern Ireland in 2009; they have been spotted in the Republic of Ireland in 2010, almost certainly having reached there with some human assistance.
Males have short antlers, which can regrow, but they tend to fight for territory with their “tusks” (downward-pointing canine teeth). The presence of these “tusks” is otherwise unknown in native British wild deer and can be discriminatory when trying to differentiate a muntjac from an immature native deer, although water deer also have visible tusks (downward-pointing canine teeth); however, they are much less widespread.
Muntjacs are of great interest in evolutionary studies because of their dramatic chromosome variations and the recent discovery of several new species. The Indian muntjac (Muntiacus muntjak) is the mammal with the lowest recorded chromosome number: The male has a diploid number of 7, the female only 6 chromosomes. Reeves’s muntjac (Muntiacus reevesi), in comparison, has a diploid number of 46 chromosomes