Mexican land birds reveal complexity in fine-scale patterns of endemism

SARA B. BERTELLI; SZUMIK, C; GOLOBOFF, PA; GIANNINI, NP; NAVARRO-SIGÜENZA, A; PETERSON, A; CRACRAFT, J

JOURNAL OF BIOGEOGRAPHY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016

0305-0270

Aim. Understandingpatterns of endemism is key to deciphering the history of biotas and settingconservation priorities, but resolving the complexity of distributionalpatterns quantitatively into areas of endemism is often a difficult task. We reporthere an analysis of a comprehensive biodiversity dataset for the study ofendemism, including virtually all vouchered records available for resident landbirds of Mexico (>100,000 georeferenced data points for all 780 species). Location. Mexico. Methods. The datasetwas analyzed with methods that recover areas without assuming prior endemicstatus for any species. This grid-based method for detecting areas of endemismconsiders co-occurrence and exclusiveness of species in alternative sets ofgeographic cells at different spatial resolutions, and finds optimal sets usingheuristic, computationally intensive searches. Results. We providethe most detailed study of endemism in Mexico to date.  Our analysis recovered 17 of 18 previouslyrecognized areas of endemism for Mexican birds, plus many additional areasclearly supported by distributional data ?totalling 33 areas of endemism atdifferent spatial scales. These areas cover 70% of the country?s surface andform a network of nested and partially overlapping regions, some of which arealso disjoint. Main conclusions. Thispicture contrasts strongly with previous conceptions of areas of endemism asnon-overlapping and spatially simple in terms of scale. Our results reveal thatendemism may be spatially complexity and shed new light on its role as a keymanifestation of biodiversity. Species recovered as endemic to these areascomprise >30% of the land birds of Mexico, with a disproportionately largefraction of those endangered.