IUCN Red List (2004) documents the extinction of 784 species (including 338 vertebrate species, 359 invertebrate species and 87 plant species) in the last 500 years. On worldwide basis, more than 15,500 species are facing the threat of extinction. At present, 12% of the bird species, 23% of mammal species, 32% of amphibian species and 31% of gymnosperm species are facing the threat of extinction in the world. Several endangered mammalian species are Panthera pandus (Leopard), Panthera leo persica (Lion), Presbytis pilaetus (capped langur) etc.