ECOLOGICAL DIVISIONS

ECOLOGICAL DIVISIONS India is divided into the following five ecological sub-regions for studying its varied wildlife.
I. The Himalayan Mountain System This region is again divided into the following three regions with their characteristic wildlife:
(a) The Himalaya Foothills Big mammals of north India like elephant, sambar, swamp deer, cheetal, hog deer, great Indian one-homed rhinoceros, wild buffalo, golden langur, etc.
(b) Western Himalayas (high altihlde region) Wild ass, wild goats (thar, markhor, ibex) and sheep (Nayan, Marcopolo's sheep, bharal or blue sheep); antelopes (chiru and Tibetan gazelle), deers (hangul or Kashmir stag and slou or Sikkim stag, musk deer); smaller mammals like marmots and pikas, etc.
(c) Eastern Himalayas Red panda, hog badgers, crest­less porcupines, goat antelopes (scrow, gora\, takins).
II. Peninsular Indian Sub-region This is a true home of Indian wildlife with two distinct zones (a) peninsular India and its extension into the drainage basin of the Ganges river system, and (b) desert region of Rajasthan.
(a) Peninsular India It is the home of wildlife thriving in tropical moist deciduous to tropical dry deciduous vegetation. Important fauna include elephant; wild boar; deers (cheetal or axis deer, hog deer, swamp deer or bursinga, sambhar); antelopes (four-homed antelope, nilgai, blackbuck, etc.); wild dog; and gaur (a bull).

(b) Indian Desert Animals are mostly burrowing ones. Among mammals rodents are the largest group. The Indian desert gerbils are mouselike rodents. Other animals are wild ass, blackbuck, desert cat, caracal, etc. Among birds the most discussed is Great Indian bustard.
III. Tropical Evergreen Forest Region or Indo-Ma­layan Sub-region The region with heavy rainfall is very rich in animals. There are wild elephants, gaur and other larger animals. Most species are tree dwellers. The most prominent ones are hoolock gibbons (only ape found in India), golden langur, capped langur or leaf monkey, etc.
IV. Andaman and Nicobar Islands These islands are houses for many species of mammals, reptiles and marine animals. Among mammals, bats and rats are predominant. They constitute about 75 per cent of the total mammals found on islands. Pigs, crab-eating macaque, palm civet and deers are other important land animals of the islands. Dugong, false killer whale and dolphin are prominent marine mammals. The islands house rare birds such as Narcondum hornbill, Nicobar pigeon and megapode.
V. Mangrove Swamps of Sunderbans Fish, small crabs, and the Dorippe (having an unusual association with sea anempne), weaver ants, spotted deer, pigs, lizards, etc., are important animal lives. The most interesting animal is the man-eater tiger of Sunderbans.