The large peninsula of Yucatán juts northwards into the Gulf of Mexico and Caribbean Sea. Being a flat, sedimentary, limestone, shallow-soiled shelf, it is geologically and topographically distinct from adjacent mainland Central America, which is formed mainly along a core of mountains, igneous in origin. This EBA comprises only a small, narrow coastal strip of the northern end of the peninsula mainly in the Mexican states of Yucatán and Quintana Roo, but also extreme north-west Campeche.

The habitat of the EBA is coastal dune scrub (often termed 'thorn forest') on a calcareous sand bar, which is usually separated from the limestone bedrock of the mainland by mangrove swamps, lagoons or sawgrass savanna. Typically the dune scrub varies in width from 70 to 2,000 m and the landward lagoons and swamps can be up to 3 km wide (Ornat and Lynch 1990). The area is coincident with the lowest rainfall in the Yucatán peninsula, being 450 mm per year (Ornat et al. 1989). According to Standley (1930), 17% of the peninsula's flora is endemic, and its northern portion (relating at least in part to this EBA) has been noted as the area with the most pronounced levels of endemism (Rzedowski and Calderón de Rzedowski 1989).

The two restricted-range bird species of the EBA share broadly similar ranges and habitats. Doricha eliza has a wider distribution, occurring along the north Yucatán coast east as far as north-east Quintana Roo, whereas Campylorhynchus yucatanicus does not reach Quintana Roo. Interestingly, there is also a small and disjunct population of D. eliza in Central Veracruz state near Veracruz City (s005; see map p. 112). Both species are resident and considered common to fairly common (Howell and Webb 1995a).

The Yucatán peninsula as a whole has nearly 20 bird species which are endemic to it, and in the original EBA analysis presented in ICBP (1992) much of the peninsula was included as an EBA. Most of these Yucatán peninsula endemics have now been found to occupy ranges larger than 50,000 km² and this EBA is one of two smaller EBAs resulting from the rationalization, the other being Cozumel (EBA 016).

Ornat and Lynch (1990) report that over the past century perhaps half of the original extent of the coastal dune scrub habitat of the peninsula has been destroyed or severely degraded by commercial cultivation of coconut palms or through development for tourism. However, they note that the northern part, which refers to this EBA, has suffered less from tourist development than has the Quintana Roo coast, and sizeable areas of native scrub still remain. Additionally, there are abandoned coconut plantations, now with regenerating vegetation, which support the bird species of the area (Ornat and Lynch 1990). For these reasons neither D. eliza or C. yucatanicus are currently considered as threatened.

Extensive portions of this EBA are included within two special Biosphere Reserves. Celustún (591 km² ) is located in north-west Campeche and adjacent north-west Yucatán, while Río Lagartos (478 km² ) lies principally along the north Yucatán coast. Both areas were designated to protect the nesting sites of Greater Flamingo Phoenicopterus ruber and waterbird feeding areas, but also support extensive areas of the coastal dune scrub important for the restricted-range species.

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: Yucatán peninsula coastal scrub. Downloaded from https://datazone.birdlife.org/eba/factsheet/9 on 23/11/2024.