The Ecomorphology of Mammalian Frugivores: A Test of Congruence Between Cranial Morphology and Feeding Behavior

University Of Massachusetts Amherst, Amherst MA

Investigators

Abstract

Ecomorphology is the study of how an organism's anatomy is associated with its ecology. Behavior, or how animals use their anatomy, is an important bridge between animals and their environments. Specifically, comparing animals abilities to perform certain tasks can provide information about the ecological roles those animals play. Modern ecomorphology studies combine analyses of anatomy, performance and relationships among animals to understand the factors underlying the diversity of organisms in the world today. Scientists studying birds and fish have found a strong association between the anatomy of the skull and feeding behavior. This study investigates whether this same strong association is typical of mammals. By investigating this relationship, this study will test fundamental associations between skull form and skull function and shed light on the basis of ecological diversity within one group of modern mammals. The subjects of this study are two distantly related groups of fruit bats - New World fruit bats and Old World fruit bats. These groups were selected for this study because they each contain an array of species that divide the fruit resources available to them in similar ways. The anatomical and behavioral diversity within these two groups make them an ideal test case for studying the interplay between skull morphology, behavioral flexibility and feeding performance. The goal of this study is to explore the relationships among cranial morphology, feeding performance, and diet, and evaluate the roles that these factors play in the ecological diversity of fruit feeding mammals. This study will: 1) provide an assessment of flexibility in feeding behavior within and between species, 2) identify peaks in feeding performance within species, 3) test fundamental associations between skull morphology and dietary habits; 4) evaluate the role of body size in feeding performance, and 5) test the hypothesis that skull morphology and feeding behavior are tightly linked and reflect variation in diet more than evolutionary history. Each of these five areas will be explored through testing explicit hypotheses using specific statistical and systematic techniques. The importance of this study lies in testing the proposition that skull morphology and feeding behavior are tightly linked in mammals. Although mammals are generally well studied, the relationship between variation in feeding performance and ecological diversity has not been investigated. This study will assess the correlation of morphology, behavior, and performance in two ecologically similar but distantly related linages - a design that provides a natural test of the strength of association among these factors.