Kay Holekamp

Kay  Holekamp
  • University Distinguished Professor
  • Directory
  • Integrative Biology
  • Ecology, Evolutionary Biology, and Behavior Program




My students and I are currently investigating how social, ecological, and endocrine variables interact during an individual's early development to influence its subsequent behavior and its reproductive success as an adult. We are conducting a long-term field study of behavioral development and associated endocrine changes in free-living spotted hyenas (Crocuta crocuta) in Kenya. Female hyenas exhibit male-like genitalia, as well as patterns of aggressive and other rank-related behaviors that are reversed from normal mammalian sex roles. These unusual sex role reversals make the spotted hyena an exciting subject for testing hypotheses about the causal factors promoting emergence of sex differences in morphology and behavior. Hyena society is remarkably similar in many respects to the societies of many old world primates, so this species is also ideal for evaluating predictions of hypotheses suggesting alternative evolutionary explanations for the evolution of big brains and great intelligence. Spotted hyenas bear small litters in which siblings often fight vigorously shortly after birth. Second, we are curious about the physiological and ecological variables that interact to influence the occurrence in space and time of mammalian exploratory behavior and emigration. We are particularly interested in the long-term fitness consequences of inter-group movements, and in the short-term physiological and social consequences of immigration. We are also studying the evolutionary forces that favor cooperation in our study animals. Finally, we are deeply concerned about the conservation of large African carnivores so we are seeking novel ways to conserve them.


  • Spotted hyenas
  • Social, ecological and endocrine variables interact during early development
  • Behavioral development and associated endocrine changes
  • Evolutionary forces that favor cooperation
  • Conservation of large African carnivores