The birds of Thailand are mainly typical of the Indomalayan realm, with affinities to the Indian subcontinent to the west, and, particularly in Southern Thailand, with the Sundaic fauna to the southeast. The northern mountains are outliers of the Tibetan Plateau, with many species of montane birds, and in winter the avifauna is augmented by migrants from the eastern Palearctic and Himalayas. That Thailand's habitats are contiguous with those of neighbouring countries explains the low number of endemic species.