Fall diet composition of Mexican duck (Anas diazi) at Lerma marsh, South Vessel, México State

Abstract

THE MEXICAN DUCK´S DIET COMPOSITION AND ITS VARIATION IN 2 CONSECUTIVE FALL PERIODS (2004-2005) WAS STUDIED AT THE LERMA MARSH, SOUTH BASIN, MEXICO STATE, INCLUDING 24 ESOPHAGEAL SAMPLES OBTAINED DURING THE HUNTING SEASON. A COMPLEMENTARY ANALYSIS USING AGGREGATED DRY WEIGHT AND FREQUENCY OF OCCURRENCE SHOWED THAN THE MEXICAN DUCK HAS A VEGETARIAN DIET DOMINATED BY AQUATIC PLANTS SEEDS, WEEDS SEEDS, CORN SEEDS AND SAGITTARIA TUBES. THE MAIN FOODS IN 2004 WERE ECHINOCHLOA HOLCIFORMIS, POLYGONUM LAPATHIFOLIUM AND P. PUNCTATUM SEEDS, WHEREAS CORN SEEDS AND SAGITTARIA MACROPHYLLA TUBERS DOMINATED THE 2005 DIET. THE SORENSEN SIMILARITY ANALYSIS OF THE DIETS SHOWED A DIET VARIATION OF 70% ON BOTH YEARS, WHICH COULD BE TO ATTRIBUTED TO ANNUAL FOOD AVAILABILITY.