This Mexican Secondary Area is found between Córdoba town in Veracruz state and Cerro Oro in northern Oaxaca, and is characterized by steep hill country of karst limestone outcrops, which are covered in semi-deciduous and evergreen forest (see map, p. 112). The area embraces the range of Sumichrast's Wren Hylorchilus sumichrasti, a cryptic species that espends the majority of its time at or near ground-level, always in closed-canopy forest, foraging in and around cracks and crevices of rocks and vegetation on the limestone outcrops. It is closely related to Navas Wren H. navai (see EBA 013 for discussion of taxonomy). H. sumichrasti, is considered threatened (classified as Vulnerable) owing to its tiny range and vulnerability to habitat destruction. Although these forested limestone outcrops are poor for cultivation compared with the surrounding flatter land, and thus have been spared from complete conversion to agriculture, they are threatened by expansion of limestone-quarrying, and in many areas the forest has an understorey of coffee plants. It appears that it is the limestone outcrops rather than the primary forest understorey that are essential for the wren, as it has been found in good numbers in shaded coffee plantations on limestone around Córdoba. Some of the species' habitat has undoubtedly been lost to the extensive Presa Miguel Alemán reservoir in northern Oaxaca, as birds have been recorded on some of the small islands created by the dam (Collar et al. 1992). There are currently no protected areas within this Secondary Area.

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: South Mexican karst forests. Downloaded from https://datazone.birdlife.org/eba/factsheet/305 on 23/11/2024.