Mammals of Sri Lanka.

Mammals (class Mammalia) are a clade of endothermic amniotes distinguished from reptiles and birds by the possession of hair, three middle ear bones, mammary glands, and a neocortex (a region of the brain). The mammalian brain regulates body temperature and the circulatory system, including the four-chambered heart. The mammals include the largest animals on the planet, the rorquals and some other whales, as well as some of the most intelligent, such as elephants, some primates and some cetaceans. The basic body type is a four-legged land-borne animal, but some mammals are adapted for life at sea, in the air, in the trees, or on two legs. The largest groups of mammals, the placentas, have a placenta which feeds the offspring during pregnancy. Mammals range in size from the 30–40 mm (1.2–1.6 in) bumblebee bat to the 33-meter (108 ft) blue whale.

Except for the five species of monotremes (egg-laying mammals), all modern mammals give birth to live young. Most mammals, including the six most species-rich orders, belong to the placental group. The three largest orders, in descending order, are Rodentia (mice, rats, porcupines, beavers, capybaras, and other gnawing mammals), Chiroptera (bats), and Soricomorpha (shrews, moles and solenodons). The next three largest orders, depending on the classification scheme used, are the primates, to which the human species belongs, the Cetartiodactyla (including the even-toed hoofed mammals and the whales), and the Carnivora (cats, dogs, weasels, bears, seals, and their relatives). While the classification of mammals at the family level has been relatively stable, different treatments at higher levels—subclass, infraclass, and order—appear in contemporaneous literature, especially for the marsupials. Much recent change has reflected the results of cladistic analysis and molecular genetics. Results from molecular genetics, for example, have led to the adoption of new groups such as the Afrotheria and the abandonment of traditional groups such as the Insectivora.

Sri Lanka has 125 species of mammals including Leopards, Monkey, Blue Whales,  and the pride of place goes to the majestic Elephant. Although rapid destruction of its habitat has depleted the Elephant population, sizeable numbers can be seen in Wasgamuwa, Minneriya, Kawudulla, Gal Oya and Udawalawe National parks and at Handapangala. Extinction also threatens the island’s biggest cat – the Leopard, although Yala & Wilpattu National parks are justifiably proud of its leopard population. Many species of deer – the Sambhur, the Hog Deer, and the Mouse deer can also be seen in the Parks.

Other mammals include the Sloth Bear, the protected Dugong, the Wild Boar, the Porcupine and Monkeys, especially the Grey Langur, which are common throughout the island. Of special interest is the endemic purple faced Leaf Monkey, found in the higher hill regions.