ESTRUCTURA Y DIETA DEL ENSAMBLE DE LOS MURCIÉLAGOS NECTARÍVOROS DE SAN MARCOS ARTEAGA, SIERRA MIXTECA, OAXACA

Abstract

Nectar-feeding bats are considered the main pollinators mammals that have a mutualistic relationship with the plants they eat. In Oaxaca State, biological studies on this phenomenon are scarce. The aim of this study was to estimate the spatial and temporal variations in the structure and diet of nectar-feeding bats in relation to food availability. The study was conducted in San Marcos Arteaga, in the Sierra Mixteca of Oaxaca, from September 2009 to August 2010, and included two sampling sites with different vegetable features (tetecheras and oak forest). The pollen collection of bats was carried out by rubbing body at the time of capture with a swab moistened with distilled water, the pollen was observed by scanning electron technique. Five species of bats were captured: Anoura geoffroyi (n=3), Choeronycteris mexicana (n=3), Leptonycteris curasoe (n=13), L. nivalis (n=11) and Choeroniscus godmani (n=2), who consumed Calliandra eriophylla, Tecoma stans, Ipomea pauciflora; and species of the genus Ipomea, Agave and Pinus; and families Cactaceae and Bombacaceae. The resource more consumed were the species of genus Agave. The highest values of diversity for bats were in the oak forest and the rainy season (dry season H’= 1.0114; rainy season H’= 1.3705; tetechera H’= 0.988; oak forest H’= 1.282) those were that presented the greatest richness and abundance of floral resources. Similarly, the sex distribution and reproductive activity of these pollinators were also influenced by the factor of food, where it showed a correlation between the peak floral abundance and richness peaks sexually active (November 2009, June and July 2010). The simple linear regression analysis indicated that the factor that had the most influence on the richness and abundance of bats, was the temporal and spatial abundance of floral resources. These results show that the structure and assembly of the diet of nectar-feeding bats are highly determined by the temporal and spatial avaialability of food and therefore the study area is an important area of distribution for theses e mammals.