Indian wildlife that comprises numerous species of birds, animals, mammals etc, is well famous for being one of the richest in the world. The Indian wildlife also contains several endangered species that are living critically on the verge of extinction. An endangered species is actually a population of an organism that is at risk of becoming extinct because it is either, (a) few in number or (b) threatened by changing environmental or predation parameters. The endangered species in India have been identified by different national and international organisations like the World Wildlife Fund (WWF), International Union for Conservation of Nature and Natural Resources (IUCN) and the Wildlife Institute of India (WII).

The environmental bodies have identified four main reasons for concern behind the extinction of endangered species in India. The reasons are (a) loss of a species as a biological entity; (b) destabilization of an ecosystem; (c) endangerment of other species; and (d) loss of irreplaceable genetic material and associated bio-chemicals. When one species goes extinct, population increases or declines often result in secondary species. There is a possibility for an unstable spiral to ensue, until other species are lost and the ecosystem structure is changed markedly and irreversibly. The endangered species in India have been divided into four main categories like the Critically Endangered (CR), Endangered (EN), Vulnerable (VU) and Threatened. This classification was done by the International Union for Conservation of Nature and Natural Resources (IUCN) and Wildlife Institute of India (WII), in the year 2004.

The number of endangered species in India is 410 species of mammals (8.86% of the world`s mammals). The mammals are spread over 186 genera, 45 families and 13 orders out of which nearly 89 species are listed as threatened in the IUCN Red List of Threatened Animals (IUCN 2006). This also includes two species that are already locally extinct from India and the species are Acinonyx jubatus and Rhinoceros sondaicus. The mammals are actually the class of vertebrate animals and they are mainly 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 mammary glands in females produce milk for the nourishment of young. The brain of mammals regulates endothermic and circulatory system, including a four-chambered heart. The mammals encompass some 5,500 species (including Humans) in the world and the species are distributed in about 1,200 genera, 152 families and up to 46 orders. However, this varies with the classification scheme.

Among all the endangered species in India, one of the most critically endangered one is the Siberian Tiger. This is a rare subspecies of tiger. The tigers, as a whole, are an endangered species. The Asian Elephants found in India have also become the victims to the ever famous `ivory poaching`. However, the most important cause of the decline of the Asian elephant is considered to be the loss of habitat. They have also been affected by persecution due to the crop damage they are perceived to cause. According to the Elephants` Preservation Act, passed in India in 1879, no wild elephant shall be killed or captured unless in a person`s self-defense, or because of damage being caused. Another endangered species in India is one of the big cats, the Golden Leopard with black marks. The number of this species has been reduced to as low as 14,000, in India.

The main reasons behind the decline of Leopard population in India have been the loss of habitat and also human population pressure on wildlife reserves in India. These reasons are also a matter of great concern for the other endangered species in India. The major reason behind the habitat loss is the spread of agriculture and teak, coffee, tea and other plantations. The Bengal Tigers were also extensively being captured for the pet trade, zoos and research, as well as for use in Oriental medicine, in the past.

The Critically Endangered species in India, as identified by the IUCN and WII include the Jenkin`s Shrew, Malabar Large-spotted Civet, Namdapha Flying Squirrel, Pygmy Hog, Salim Ali`s Fruit Bat, Sumatran Rhinoceros, and the Wroughton`s Free-tailed Bat. The list of Endangered species in India include the Asiatic Lion, Asiatic Black Bear, Desert Cat, Great Indian Rhinoceros, Hispid Hare, Hoolock Gibbon, Kashmir Stag/ Hangul, Lion-Tailed Macaque, Malabar Civet, Markhor, Nayan Ovis, Nilgiri Leaf Monkey, Pygmy Hog, Andaman Shrew, Andaman Spiny Shrew, Indian Elephant or Asian Elephant, Banteng, Blue Whale, Capped Leaf Monkey, Chiru, Fin Whale, Ganges River Dolphin, Golden Leaf Monkey, Hispid Hare, Asian arowana, Loggerhead Sea Turtle, Hoolock Gibbon, Indus River Dolphin, Kondana Soft-furred Rat, Lion-Tailed Macaque, Markhor, Marsh Mongoose, Nicobar Shrew, Nicobar Tree Shrew, Nilgiri Tahr, Parti-coloured Flying Squirrel, Peter`s Tube-nosed Bat, Red Panda, Sei Whale, Servant Mouse, Snow Leopard, Tiger, Wild Water Buffalo, and the Woolly Flying Squirrel.

Apart from the Critically Endangered and the Endangered Species in India, the IUCN and WII have also identified several species as Vulnerable in India. These species include the Asiatic Wild Dog/ Dhole, Banteng Bos javanicus, Brow-antlered Deer, Brown Bear, Brown Palm Civet, Clouded Leopard, Common Otter, Dugong/ Seacow, Ganges River Dolphin, Gaur, Goral, Grey Indian Wolf, Himalayan W-toothed Shrew, Himalayan Musk Deer, Himalayan Shrew, Jackal Canis aureus, Andaman Horseshoe Bat, Andaman Rat, Argali, Asiatic Black Bear, Asiatic Golden Cat, Asiatic Wild Ass, Assamese Macaque, Back-striped Weasel, Barasingha, Bare-bellied Hedgehog, Blackbuck, Brown fish owl, Central Kashmir Vole, Clouded Leopard, Day`s Shrew, Dhole, Dugong, Eld`s Deer, Elvira Rat, Eurasian Otter, Fishing Cat, Four-horned Antelope, Gaur, Himalayan Tahr, Humpback Whale, Indian Giant Squirrel, Irrawaddy Squirrel, Jerdon`s Palm Civet, Kashmir Cave Bat, Kerala Rat, Khajuria`s Leaf-nosed Bat, Kolar Leaf-nosed Bat, Lesser Horseshoe Bat, Mainland Serow, Malayan Porcupine, Mandelli`s Mouse-eared Bat, Marbled Cat, Mouflon (or Urial), Nicobar Flying Fox, Nilgiri Leaf Monkey, Nilgiri Marten, Nonsense Rat, Pale Grey Shrew, Palm Rat, Red Goral, Royal Bengal Tiger, Rock Eagle-owl, Rusty-spotted Cat, Sikkim Rat, Sloth Bear, Slow Loris, Smooth-coated Otter, Sperm Whale, Sri Lankan Giant Squirrel, Sri Lankan Highland Shrew, Stumptail Macaque, Takin, Wild Goat, Wild Yak and the Lesser Panda. The species like the Indian Wild Ass, the Leopard and the Red Fox have been identified as the Threatened Species in India.