We used stable carbon and nitrogen isotope analyses to test the hypothesis that nectar-feeding bats Leptonycteris curasoae and Glossophaga longirostris depend on cacti and agaves as food sources in Venezuelan arid zones and to compare their trophic positions. We measured the isotopic compositions of muscle tissue in the 2 species during 1 year at 3 arid locations. Overall carbon isotopic composition (∂13C) of L. curasoae (−11.76‰) and G. longirostris (−13.28‰) resembled values characteristic of columnar cacti and agaves (−12.47‰), which have in common the crassulacean acid metabolism (CAM) photosynthetic pathway. L. curasoae appears to be more dependent on cacti and agaves (98% CAM in the diet) than G. longirostris (85% CAM in the diet). CAM dependence, as we designate dependence on cacti and agaves, was evidenced across sites. Level of CAM dependence slightly varied over the year only in G. longirostris. We concluded that the 2 species of bats mainly rely on CAM plants in Venezuelan arid zones. Overall nitrogen isotopic composition (∂15N) did not differ between L. curasoae (15.87‰) and G. longirostris (15.37‰). Although our results suggest that the 2 bats occupy the same trophic position, no conclusive evidence supported this observation. The strong interdependence between these bats and their host CAM plants in northern South America suggests that a disturbance affecting 1 component of the interaction would have a strong effect on the other.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.