The montane bird fauna is not well represented in Khao Yai, not only because the park is relatively remote from the higher forested mountains of the north and west, but partly because it has only small, isolated areas of unexceptionally high mountain tops.

Khao Yai’s bird fauna is chiefly composed of those lowland and hill slope(submontane) birds, which have fairly wide latitudinal ranges. Some other lowland species, such as Siamese Fireback, Pompadour Pigeon and Javan Frogmouth, which may once have been abundant in the evergreen forests which formerly covered the surrounding plain, are found only at extremely low density around the Khao Yai headquarters area.