Off-campus UMass Amherst users: To download dissertations, please use the following link to log into our proxy server with your UMass Amherst user name and password.

Non-UMass Amherst users, please click the view more button below to purchase a copy of this dissertation from Proquest.

(Some titles may also be available free of charge in our Open Access Dissertation Collection, so please check there first.)

The evolution of cranial morphology, feeding performance and behavior in neotropical leaf-nosed bats (Chiroptera: Phyllostomidae)

Sharlene E Santana Mata, University of Massachusetts Amherst


Morphology can play a major role in ecological diversification and adaptive radiation when it consistently enhances performance and behavior. Here I investigate how cranial and dental morphology, feeding performance and behavior relate to one another and to the dietary radiation in Neotropical leaf-nosed bats (Family Phyllostomidae). First, I build a 3D biomechanical model to investigate the mechanism connecting cranial morphology and bite performance (bite force) and how bats with different diets vary in biomechanical parameters predicting bite force. The model demonstrates that cranial morphology is a strong predictor of bite force variation, and that bats differ in biomechanical predictors of bite force when they are classified according to dietary hardness. Second, I investigate the relationship between biting behavior and bite force across phyllostomids. My results indicate that bats modulate their performance by changing their biting behaviors to maximize bite force when feeding on hard foods. Using phylogenetic correlations and ancestral state reconstructions, I provide evidence for correlated evolution of behavior and performance, and rapid evolution in these traits that coincided with the use of plant resources. Third, I investigate the trends in molar complexity, chewing behavior and efficiency in breaking down prey across phyllostomids with different diets. My results illustrate that frugivores exhibit a higher dental complexity than insectivores and omnivores, and that the latter groups achieve higher performance in insect breakdown through higher molar complexity and chewing behavior. Finally, I investigate if other behavioral traits relevant to fitness have shaped the evolution of the skull morphology, using roost excavation in Lophostoma silvicolum as a model system. Through finite element analysis, I provide support for the prediction that the skull of L. silvicolum presents adaptations for roost excavation, in the form of a stronger skull. When all my findings are considered there is evidence that, although morphology can strongly predict performance, behavior plays an important role in modulating performance, and selection on this ability could have contributed to the ecological diversification of phyllostomids. Overall, the dietary radiation of phyllostomids, in particular the use of plant resources, was associated with dramatic changes in cranial and dental morphology, feeding performance and behavior.

Subject Area

Biology|Evolution and Development|Biomechanics

Recommended Citation

Santana Mata, Sharlene E, "The evolution of cranial morphology, feeding performance and behavior in neotropical leaf-nosed bats (Chiroptera: Phyllostomidae)" (2010). Doctoral Dissertations Available from Proquest. AAI3427567.