Blaire Van Valkenburgh

Professor

LS 5312
Box 951606
Los Angeles, CA 90095-1606
Campus mailcode: 160603
Tel: (310) 794-9398 /(310) 825-4669
bvanval@ucla.edu
Personal Website

Keywords: Africa, Medicine, Science

Research Interests

The questions which interest me are both ecological and evolutionary, and I approach them from the perspective of a paleobiologist and functional morphologist. My organisms of choice are vertebrates, particularly mammals. In several studies, I explored the effects of competition, prey diversity and environment on predator morphologies within past and present communities. In this work, I used the tools of biomechanics to infer critical aspects of carnivore feeding and locomotor behavior from skeletal and dental morphology. For example, quantitative indices of claw shape, limb proportions, joint mechanics and body size were used to determine locomotor behavior. Similar indices describing relative tooth size and shape indicated dietary content among living and extinct predators. Based on these morphologic indices of behavior, I was able to compare the pattern of ecological separation among coexisting carnivores in several ancient and modern communities, all of which differed in prey diversity and/or vegetation structure. Future work will expand the array of time periods sampled and attempt to follow the course of morphological divergence within a single community over several million years. Most recently, I completed an analysis of tooth fracture frequencies in the large carnivores of the Pleistocene Rancho La Brea tarpits. Comparisons with a sample of modern carnivores, such as hyenas and wolves, revealed that the big meat-eaters of the tar pits suffered up to five times more tooth breakage. Apparently, the now extinct dire wolves, American lions, and sabertooth cats, were forced to consume their kills more fully, chewing the bones, and thereby injuring their teeth. Carnivores eat more bone when prey are difficult to acquire and thus the high tooth fracture frequencies suggest competition for food was more intense ten to thirty thousand years ago. Studies underway include an exploration of the growth and development of bite strength in members of a captive population of spotted hyenas, analysis of feeding behavior in large African carnivores, and further studies of tooth fracture frequencies in additional mammalian species.