Spatial and temporal composition of the avifauna from small coastal wetlands and adjacent habitats in northwestern Baja California, Mexico

Abstract

We studied the spatial and temporal composition of the avifauna from 13 small coastal wetlands and adjacent habitats in northwestern Baja California, Mexico, between February and December 2002. A total of 17,978 individuals belonging to 187 species, 121 genera and 47 families were registered. The richest families in species were Anatidae (17), Scolopacidae (17) and Laridae (12). The wetlands showing the highest specific richness were El Rosario (126), Santo Tomás (107) and La Misión (95), which pooled represented 86% of the total avifauna. Seventy-six species (41%) were permanent residents, 73 (39%) seasonal visitors and 38 (20%) occasional visitors. On the basis of presence or absence of species, four groups of wetlands are distinguished: (a) San Simón, (b) La Salina, (c) El Descanso-El Ciprés, and (d) a group of nine sites that is subdivided into two branches with four and five localities each, one (d.1) consisting of San Telmo-Santo Tomás-El Rosario-La Misión and the other (d.2) of San Rafael-San Miguel-El Salado-Santo Domingo-Cantamar. The presence or absence of a permanent water body, the types of habitat and the presence or absence of anthropogenic influence at each locality were factors that contributed to the grouping of these wetlands. Specific richness and abundance were correlated with habitat diversity. Breeding evidence was documented for 20 species.