ehavior can be defined as the series of steps that organisms use to accomplish specific tasks. We feel that in order to fully understand the importance of morphology, it is essential to understand the ways in which animals use it, via behavior, to perform tasks that are critical to their daily lives. Currently, we are most interested in behaviors that mediate interactions between mammals and their physical environment that occur during feeding. Our primary questions are, to what extent can mammals modify feeding behavior for different tasks? And, is there a link between morphology and behavioral plasticity? To answer these questions, we document variation in feeding behavior among species using wild-caught bats at field sites in Panama, Costa Rica, Australia, and Papua New Guinea and captive animals housed at the Lubee Foundation.
To document feeding behavior, we conduct experiments in which bats are given fruits of known size and hardness to eat. Videotape of animals handling and eating the fruits is brought back to the lab for analysis. Animals are not harmed during these experiments and all are released in good health at the end of the studies. To date, we have documented the location of bites along the tooth row, the frequencies of bites and chews, body postures, and the use of the wings and feet to manipulate food items in 14 species.
We have documented significant variation in feeding behavior among both the New World leaf-nosed and the Old World fruit bats. We have also found that species exhibit different levels of behavioral plasticity in their approach to foods of different hardness. While the feeding behavior of some species is essentially invariant, others switch to more mechanically efficient biting styles when confronted with harder food items. In addition to describing behavioral variation, we use modern comparative techniques (independent contrasts and squared change parsimony) to evaluate correlated changes in cranial morphology and feeding behavior at several taxonomic scales.
