Composicion taxonómica y ecológica de la avifauna de los ríos El Mayor y Hardy, y áreas adyacentes en el valle de Mexicalí, Baja California, México

Abstract

THE TAXONONIC AND ECOLOGICAL COMPOSITION OF THE AVIFAUNA OF EL MAYOR AND HARDY RIVERS, AND ADJACENT AREAS, IN THE VALLEY OF MEXICALI, BAJA CALIFORNIA, MEXICO, WAS STUDIED SEASONALLY FOR TWO YEARS (FEBRUARY 1994 TO DECEMBER 1995). A TOTAL OF 108 SPECIES BELONGING TO 88 GENERA AND 35 FAMILIES WERE REGISTERED. SIXTY SPECIES WERE PHOTOGRAPHED IN SITU AND 44 SPECIES WERE COLLECTED AND DEPOSITED IN THE BIRD COLLECTION OF THE FACULTAD DE CIENCIAS, UNIVERSIDAD AUTONOMA DE BAJA CALIFORNIA, AT ENSENADA. THE FAMILY EMBERIZIDAE REGISTERED THE HIGHEST SPECIES NUMBER (1() FOLLOWED BY ANATIDAE AND SCOLOPACIDAE (11 EACH). ACCORDING TO THE TEMPORAL OCCURRENCE OF THE AVIFAUNA, 31 SPECIES WERE RESIDENTS, 50 WINTER VISITORS, 24 SUMMER VISITORS, TWO CASUAL VISITORS, AN ONE TRANSENT. DURING 1994, THE HIGHEST NUMBER OF SPECIES WAS REGISTRED IN NOVEMBRER (53) AND THE LOWEST IN FEBRUARY (34); HOWEVER, IN 1995, THE HIGHEST NUMBER OF SPECIES OCCURED IN DECEMBER (58) AND THE LOWEST IN SEPTEMBER (49).