Intraspecific and interspecific partitioning of foraging times among three tropical bat species in La Sierra Norte, Oaxaca, Mexico
The unique niche of the bat has led to its extensive diversification around the world. Vital to many ecosystems, bats in the Neotropical zones' are especially important to the existence of other species that depend on them for pollination, seed dispersal, and pest eating. Understanding how ecologically similar bat species coexist is necessary in order to examine the dynamics of community interactions. This study investigates one possible mechanism of coexistence: a temporal partitioning of resources in order to avoid interference competition. I examined interspecific differences in hourly activity between the three most abundant bat species in the tropical rainforest of the Sierra Norte, Oaxaca, Mexico (Dermanura tolteca, Sturn ira ludovici, and Centurio senex); as well as intraspecific differences between the sexes, age-classes, and reproductive states. A total of 187 individuals over a period of 15 months, caught using the capture-recapture method, were analyzed with the Chi Square statistical test. The results of the interspecific study found a temporal partitioning of foraging times between S. ludovici and C. senex in the rainy season and between D. tolteca and S. ludovici in the dry season. This partitioning may take place due to the decreased availability of resources in the dry season and an increased need to avoid interference while feeding. Intraspecifically, I found no temporal partitioning between sexes, while only D. tolteca demonstrated a temporal partitioning among age-classes. Lactating females were captured at all hours of the night, an effect of the increase in energy demands of producing milk. Future studies could investigate spatial partitioning, diet partitioning, and fluxes of Ficus spp. availability between the seasons in order to further elucidate the mechanisms that enable coexistence, an important component in designing conservation programs.