Revisiting the biogeographical regionalization of the Pacific Lowlands biogeographical province using bird distributional data

The individual tracks of 47 bird species endemic to the Pacific Lowlands biogeographical province, which belongs to the Mesoamerican dominion of the Neotropical region, were used to revise its biogeographical regionalization. As a result, the six biogeographical districts previously recognized are classified in two subprovinces: the Coastal Lowlands of Nayarit-Sinaloa subprovince, stat. nov., which includes the Sinaloan, Tres Marías Islands, Revillagigedo Islands, and Guerreran districts; and the Coastal Lowlands of Southwestern Mexico subprovince, stat. nov., which includes the Tehuanan and Tapachultecan districts. Bird species supporting the biogeographical subprovinces and districts recognized are listed. The recognition of the subprovinces encompassing the districts represents an improvement of this biogeographical regionalization.