The area is ecologically sensitive to development and was declared an ecological hotspot in 1988 through the efforts of ecologist Norman Myers. The area covers five percent of India's land with 27% of all species of higher plants in India (4,000 of 15,000 species) are found here and 1,800 of these are endemic to the region. The range is home to at least 84 amphibian species, 16 bird species, seven mammals, and 1,600 flowering plants which are not found elsewhere in the world. The Government of India established many protected areas including 2 biosphere reserves, 13 National parks to restrict human access, several wildlife sanctuaries to protect specific endangered species and many Reserve Forests, which are all managed by the forest departments of their respective state to preserve some of the ecoregions still undeveloped. The Nilgiri Biosphere Reserve comprising 5,500 square kilometres (2,100 sq mi) of the evergreen forests of Nagarahole and deciduous forests of Bandipur in Karnataka, adjoining regions of Wayanad-Mukurthi in Kerala and Mudumalai National Park-Sathyamangalam in Tamil Nadu forms the largest contiguous protected area in the Western Ghats.[20] Silent Valley in Kerala is among the last tracts of virgin tropical evergreen forest in India.[21][22]