Research

Work in my lab focuses on the ontogenetic development, physiological substrates, and evolution of mammalian behavior. My students and I are currently pursuing various lines of research investigating how social , ecological, and physiological variables interact during an individual’s early development to influence its subsequent behavior and its reproductive success as an adult.

In one line of research, my students and I are conducting a long-term behavioral field study of free-living spotted hyenas in Kenya. Females exhibit patterns of aggressive and other rank-related behaviors that are reversed from normal mammalian sex roles, and these role-reversals make the spotted hyena an exciting subject for testing hypotheses about the causal factors promoting emergence of behavioral sex differences. Hyena society is remarkably like the societies of many old-world primates, yet carnivores and primate lines diverged over 90 million years ago. This makes the spotted hyena an outstanding model species in which to test hypotheses about the selective forces shaping the evolution of social behavior and social cognition in mammals. Another line of research in my laboratory addresses questions about the causes and consequences of animal movements, with particular attention to natal dispersal movements by young male mammals. I am curious about the physiological and ecological variables that interact to influence the occurrence in space and time of mammalian exploratory and dispersal behaviors. I am also interested in the long-term fitness consequences of dispersal, and in the short-term physiological and social consequences of dispersal for emigrants. Using both field and laboratory approaches, my students and I are investigating these problems in rodents and carnivores.

Finally, my students and I are becoming increasingly heavily involved with wildlife conservation efforts in Africa. We have adopted approaches utilizing molecular genetic and Geographic Information Systems (GIS) techniques to evaluate gene flow in relation to animal movements, and responses by hyenas and other large carnivores to various types of anthropogenic disturbances. We are also attempting to determine why some large carnivores can coexist even in the face of intensive interspecific competition whereas other species are quickly driven to extinction under the same circumstances.