Geographic scale effects on ecological distribution of Mexican birds

Abstract

THE ROLE OF SPATIAL SCALE IN INFLUENCING ECOLOGICAL AND GEOGRAPHIC DISTRIBUTIONS OF 20 BIRDS SPECIES IN MEXICO WAS EXPLORED BY VARYING THE EXTENT OF SPATIAL AVERAGING AROUND KNOWN OCCURRENCE SITES. CATEGORICAL DATA FOR FOUR ECOLOGICAL CHARACTERISTICS (POTENTIAL VEGETATION, MEAN ANNUAL TEMPERATURE, MEAN ANNUAL PRECIPITATION AND ELEVATION) WERE USED TO ASSESS ASSOCIATIONS BETWEEN SPECIE'S OCURRENCES AND REGIONAL ENVIRONMENTS, AT 10 NEIGHBORHOOD SIZES (9-10000 KM2), SPECIE'S DISTRIBUTIONS DEPENDED ON DIFFERENT ENVIRONMENTAL ATTRIBUTES AT DISTINCT SPATIAL SCALES, AND SPECIES DIFFERED IN THEIR SCALES OF RESPONSE TO ENVIRONMENTS. A MULTI-SCALE APPROACH IS THUS KEY TO UNDERSTANDING DISTRIBUTIONAL PATTERNS OF SPECIES, AND FOR IDENTIFICATION OF CRITICAL ENVIROMENTAL FACTORS IN SPECIES ECOLOGICAL DISTRIBUTIONS.