as, chapories, which provide retreats and shelter for animals during floods. Many artificial chapories have been built with the help of the Indian Army to ensure the safety of the animals. Kaziranga is one of the largest tracts of protected land in the sub-Himalayan belt, and due to the presence of highly diverse and visible species, has been described as a "biodiversity hotspot". The park is located in the Indomalayan realm, and the dominant ecoregions of the region are Brahmaputra Valley semi-evergreen forests of the tropical and subtropical moist broadleaf forests biome, and the frequently-flooded Terai-Duar savanna and grasslands of the tropical and subtropical grasslands, savannas, and shrublands biome. Kaziranga is also surrounded by lush green tea plantations, most of them contributing heavily to Assam's economy. Climate The park experiences three seasons: summer, monsoon, and winter. The winter season, between November and February, is mild and dry, with a mean high of and low of . During this season, beels and nullahs (water channels) dry up. The summer season between March and May is hot, with temperatures reaching a high of . During this season, animals usually are found near water bodies. The rainy monsoon season lasts from June to September, and is responsible for most of Kaziranga's annual rainfall of . During the peak months of July and August, three-fourths of the western region of the park is submerged, due to the rising water level of the Brahmaputra. It was found that 70% of the National Park was flooded as on 3 August 2016. The flooding causes most animals to migrate to elevated and forested regions outside the southern border of the park, such as the Mikir hills. 540 animals, including 13 rhinos and mostly hog deers perished in unprecedented floods of 2012. However, occasional dry spells create problems as well, such as food shortages and occasional forest fires. Fauna Kaziranga contains significant breeding populations of 35 mammalian species, of which 15 are threatened as per the IUCN Red List. The park has the distinction of being home to the world's largest population of the Indian rhinoceros (2,401), wild water buffalo (1,666) and eastern swamp deer (468). Significant populations of large herbivores include indian elephants (1,940), gaur (1300) and sambar (58). Small herbivores include the chital, Indian muntjac, Indian boar and Indian hog deer. Kaziranga has the largest population of the Wild water buffalo anywhere accounting for about 57%