Food habits of some Costa Rican bats

Resumen

Dietary habits of 42 species of Costa Rican bats were studied by examinatíon of feces, by stomach analysis and by identification of pollen grains adhering to the fur. Food items were identified to a finer level than offered in previous literature and not merely as "plant material", "insects" or "vertebrate food" . Although the sample size for some species prohibits generalizations, the analysis reveals that many genera, supposed to be nectarivorous, eat only insects, primarily Lepidoptera, during April, May and June and that although there may be some overlap in particular food items in the eliets of closely related bats, the major ¡tems sought by each bat are different.

Generic competition, and in some cases, specific competition for food is low. Because bats are of considerable usefulness in controlling insects, in pollination, ancl in seed dispersal, a plea is made for bat conservation by using the technique of guano analysis rather than sacrificing bats for stomach analysis. The former technique gives equivalent results and proves easier for the investigator.