Patrones biogeográficos de la riqueza de especies y el endemismo de la avifauna en el oeste de México

Acta Zoológica Mexicana (nueva serie) 01/2004;
Source: DOAJ

ABSTRACT Se analizaron los patrones de riqueza y endemismo de la avifauna en el oeste de México, desde el norte de Sonora hasta el sureste de Chiapas. La región fue dividida en 24 transectos para ser usados como unidades de estudio, y los análisis desarrollados con base en registros de distribución puntual obtenidos de colecciones científicas y bibliografía y con la ayuda de un sistema de información geográfica. Para el reconocimiento de los patrones biogeográficos generales y la regionalización de la zona se utilizaron análisis de parsimonia de endemismos (PAE) y de tasas de recambio de especies, teniendo en cuenta una propuesta taxonómica alternativa para la avifauna mexicana. Se registró un total de 783 especies de aves terrestres, de las cuales 157 poseen alguna categoría de endemismo. Los datos sugieren que existe una tendencia al aumento de la riqueza de especies hacia el sur, mientras que la riqueza de endemismos es mayor hacia el centro del área de estudio y menor hacia los extremos norte y sur. Los análisis de atenuación y de PAE revelaron la existencia de tres grupos principales de áreas: uno ubicado en la sección sur, que comprende desde el este de Oaxaca hasta el sur de Chiapas; otro en la porción norte, abarcando desde el norte de Sonora hasta el norte de Nayarit y Jalisco; y un último para la porción central, desde el sur de Jalisco y el noroeste de Colima hasta el este de Oaxaca, así como la existencia de varios subgrupos al interior de estos.

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