Muntjacs ( ), also known as the barking deer or rib-faced deer, are small deer of the genus Muntiacus native to South Asia and Southeast Asia. Muntjacs are thought to have begun appearing 15–35 million years ago, with remains found in Miocene deposits in France, Germany and Poland. Most species are listed as Least Concern or Data Deficient by the IUCN, although others such as the black muntjac, Bornean yellow muntjac, and giant muntjac are Vulnerable, Near Threatened, and Critically Endangered, respectively. Name The present name is a borrowing of the Latinized form of the Dutch , which was borrowed from the Sundanese mēncēk. The Latin form first appeared as in Zimmerman in 1780. An erroneous alternative name of Mastreani deer has its origins in a mischievous Wikipedia entry from 2011 and is incorrect. Description The present-day species are native to Asia and can be found in India, Sri Lanka, Myanmar, Vietnam, the Indonesian islands, Taiwan and Southern China. Their habitat includes areas of dense vegetation, rainforests, monsoon forests and they like to be close to a water source. They are also found in the lower Himalayas (Terai regions of Nepal and Bhutan). An invasive population of Reeves's muntjac exists in the United Kingdom and in some areas of Japan. In the United Kingdom, wild deer descended from escapees from the Woburn Abbey estate around 1925. Muntjac have expanded rapidly, and are present in most English counties and also in Wales, although they are less common in the north-west. The British Deer Society in 2007 found that muntjac deer had noticeably expanded their range in the UK since 2000. Specimens appeared in Northern Ireland in 2009, and in the Republic of Ireland in 2010. 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. Tusks 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 an identifying feature to differentiate a muntjac from an immature native deer. Water deer also have visible tusks but they are much less widespread. Although these tusks resemble those of both water deer and the musk deer, the muntjac is not related to either of these (and they are not