Effect of drought conditions on the diet of insectivorous bat species: a molecular diet study
The effect of drought on the diets of four insectivorous bat species (Antrozous pallidus, Myotis thysanodes, M. yumanensis, and Parastrellus hesperus) was assessed using cytochrome oxidase-I mini-barcodes organized into molecular operational taxonomic units. I hypothesized that there would be a significant difference between diet diversity in the drought and non-drought years, the species would feed more opportunistically during the drought year, per optimal foraging theory, and there would be low dietary overlap between years. Fecal samples were collected in Big Bend National Park (Brewster Co., TX). Diet diversity differed between years for all species, excluding A. pallidus. Diet diversity was greater during the drought year for A. pallidus and P. hesperus. Antrozous pallidus exhibited high dietary overlap (0.608) between the years and overlap values for the other three species was low (0.027 - 0.149). Overall, no two bat species in this analysis changed their diet similarly in response to drought conditions.