Like its flora, Madagascar's fauna is diverse and exhibits a high rate of endemism. Lemurs have been characterized as "Madagascar's flagship mammal species" by Conservation International. In the absence of monkeys and other competitors, these primates have adapted to a wide range of habitats and diversified into numerous species. As of 2012, there were officially 103 species and subspecies of lemur. They are almost all classified as rare, vulnerable, or endangered. A number of other mammals, including the cat-like fossa, are endemic to Madagascar. Over 300 species of birds have been recorded on the island, of which over 60 percent are endemic. The island is home to two-thirds of the world's chameleon species, including the smallest known, and researchers have proposed that Madagascar may be the origin of all chameleons. Endemic fish of Madagascar include two families, 15 genera and over 100 species, primarily inhabiting the island's freshwater lakes and rivers.