Because of its broad altitudinal range and the cool climate of its upper reaches, the park supports the largest number of bird species of any site in Thailand. The Center for Wildlife Research at Mahidol University records a present total of 362 species and expects addition many at the summit are migrants from northern Asia. Species restricted to Doi Inthanon are Ashy-throated Warbler and an endemic race of the Green-tailed Sunbird; the park is the only site where the Chestnut-bellied Rock-Thrush and the Yellow-bellied Flower pecker are known to over summer and probably breed.