Southern Sierra Madre Oriental

Country/Territory Mexico
Area 31,000 km2
Altitude 900 - 3500 m
Priority urgent
Habitat loss major
Knowledge incomplete

General characteristics

This EBA includes a number of mountain ranges of eastern Mexico, principally within the Sierra Madre Oriental and the Sierra Madre de Oaxaca. The northern end of the EBA begins in the Sierra Madre Oriental from southern Tamaulipas and eastern San Luis Potosí southwards through Hidalgo, Puebla and Veracruz states. South from there it runs through Oaxaca state (where the many sierras such as Juárez, Aloapaneca and Zempoaltepec are often referred to as the Sierra Madre de Oaxaca) in a north-west to south-east direction until it ends near the Isthmus of Tehuantepec in eastern Oaxaca. The northern end of the EBA lies south of the extreme southern end of the Northern Sierra Madre Oriental (EBA 010) and the upper limits of the North-east Mexican Gulf slope (EBA 011). In Puebla and Veracruz the topography is very complicated and it is there that the EBA lies next to the eastern end of the trans-Mexican range (EBA 006 in part).

The predominant habitats of this EBA are pine and pine-oak forest, with humid evergreen montane forest (including cloud forest) in the wettest parts of the EBA. The Sierra de Oaxaca appears to have high levels of plant endemism especially in the evergreen montane forests such as the Sierra de Juárez in north Oaxaca (Lorence and Mendoza 1989).

Restricted-range species

All of the restricted-range birds are forest species, with humid montane forest being a particularly important habitat, though there are some marked distributional differences between the species. Glaucidium sanchezi is currently known only from the forests of southern Tamaulipas and eastern San Luis Potosí at the northern end of the EBA, but it has been suggested that it should be looked for in intervening areas between there and central Veracruz (Howell and Robbins 1995, Howell and Webb 1995a). Dendrortyx barbatus overlaps with G. sanchezi in eastern San Luis Potosí (e.g. Cerro San Antonio) and with the other species in Puebla and Veracruz, which marks the northern part of the range of Cyanolyca nana, a bird also found in Sierras Aloapaneca and Zempoaltepec in Oaxaca. Campylorhynchus megalopterus is found in the mountains of western Veracruz and Oaxaca but is also present in the trans-Mexican range (EBA 006).

Glaucidium sanchezi was traditionally considered a subspecies of Least Pygmy-owl G. minutissimum until a recent taxonomic review based on plumage, morphology and vocalizations recommended the complex be split into six species (Howell and Robbins 1995), and this course is followed here.

Species IUCN Category
Bearded Wood-partridge (Dendrortyx barbatus) VU
Tamaulipas Pygmy-owl (Glaucidium sanchezi) NT
Dwarf Jay (Cyanolyca nanus) NT
Grey-barred Wren (Campylorhynchus megalopterus) LC

Important Bird Areas (IBAs)
IBA Code Site Name Country
MX150 Centro de Veracruz Mexico
MX148 Río Metlac Mexico
MX015 Sierra de Zongolica Mexico
MX252 Sierra de Zongolica-Tenango Mexico
MX045 Sierra del Abra - Tanchipa Mexico
MX011 Sierra Norte de Oaxaca Mexico
MX249 Tlanchinol y Bosques de Montaña del Noreste de Hidalgo Mexico

Threat and conservation

The majority of the forests of this EBA have already been lost or degraded, and today this destruction continues through logging, agricultural expansion, firewood-gathering, road and associated tourist developments, sheep-ranching and overgrazing, as well as intensive urbanization (Dinerstein et al. 1995).

This habitat destruction is the main reason for the threatened status of Dendrortyx barbatus and Cyanolyca nana. Several Key Areas for these birds have been identified by Wege and Long (1995), but they have not been recorded at most sites for more than 20 years, being known with certainty to occur in only a couple. Cerro San Felipe in the Sierra Aloapaneca is the only current site for C. nana, in spite of many bird surveys in parts of its former range (A. T. Peterson in litt. 1995). Coatepec in Veracruz (Gómez de Silva and Aguilar Rodríguez 1994), and Tlanchinol in Hidalgo (Howell and Webb 1992b) are the only two localities where D. barbatus has been seen in the past 10 years.

There are some protected areas within the EBA, but notably few in the Oaxacan part, a region which holds some of the most diverse and extensive of Mexico's remaining montane forests. Encouragingly, this gap is now recognized, and initiatives to create a protected area in the Cuasimulco area of the Sierra de Juárez are under way (e.g. Salas et al. 1994).

Recommended citation
BirdLife International (2023) Endemic Bird Areas factsheet: Southern Sierra Madre Oriental. Downloaded from http://datazone.birdlife.org/eba/search on 09/06/2023.