The mammals are the class of vertebrate animals characterized by the presence of mammary glands, the presence of hair or fur; specialized teeth; the presence of a neocortex region in the brain; and endothermic or 'warm-blooded' bodies. The brain regulates endothermic and circulatory system, including a four-chambered heart. In India there are 410 species, 186 genera, 45 families and 13 orders of which nearly 89 species are listed as threatened in the International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Animals (IUCN 2006).

The gayal (Bos frontalis), also known as mithun, is a large semi-domesticated bovine distributed in Northeast India, Bangladesh, northern Burma and in Yunnan, China. Gayals are essentially inhabitants of hill-forests. In India, semi-domesticated gayals are kept by several ethnic groups living in the hills of Tripura, Mizoram, Assam, Arunachal Pradesh, and Nagaland. The gayal is the state animal of Arunachal Pradesh and Nagaland. Gayals play an important role in the social life of the people in Arunachal Pradesh. Marriages are not fixed until the bridegroom's family gives at least one gayal to the bride's household.

IUCN Status: Vulnerable (VU) Endangered (EN) Least Concern (LC) Photo: