This IBA includes the Cuilco Mountains and the valley west of the city of Nenton, which is the southern limit of the central valley of Chiapas, Mexico.
Cuilco is important for species of the North Central American Highlands (8 species recorded), including populations of two threatened species, Highland Guan (Penelopina nigra) and Pink-headed Warbler (Ergaticus versicolor). The site supports biome-restricted species of the Madrean Highlands (25 species recorded) and the Pacific Arid Slope (5 species). Recent ornithological information is limited to two rapid assessments (Sandoval 2000, Pérez 2006).
BirdLife International (2020) Important Bird Areas factsheet: Cuilco. Downloaded from http://www.birdlife.org on 08/04/2020.