Mammalian Behavioral Development Under Contrasting Regimes of Interspecific Competition

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Mammalian behavioral development under contrasting regimes of interspecific competition.Proposal # IBN0343381PIs: Kay E. Holekamp, Michigan State University Laura Smale, Michigan State University Jeffrey A. French, University of Nebraska at Omaha NON-TECHNICAL ABSTRACT Little is currently known about how the tendency to engage in risky behavior varies across the life-span in mammals, or how the behavior of young mammals varies with ecological circumstances. In most parts of Africa, lions (Panthera leo) and spotted hyenas (Crocuta crocuta) are the most common large carnivores, and these two species compete regularly for food. Here hypotheses will be tested suggesting that risk-sensitive behavior exhibited by free-living hyenas is affected by age and by competitive interactions with lions. Naturally-occurring variation will be documented in ranging behavior, vigilance, and risky behaviors shown by hyenas during interactions with lions over food. In addition, two playback experiments will inquire how age and local lion density influence hyenas' decisions regarding whether to approach or avoid recorded lion roars when these are broadcast from a hidden speaker. Concentrations of excreted stress hormones will be measured in hyena feces to determine whether stress physiology in these animals is affected by age or by local competition with lions. Measures of naturally-occurring behavior, experimental results, and hormone concentrations will be compared among hyenas at three different developmental stages in two Kenyan national parks in which ratios of resident hyenas to lions differ greatly. Finally, in collaboration with the Kenya Wildlife Service, methods will be developed for effective monitoring of large carnivores, and these methods will later be applied in several other national parks in Kenya. This research will thus combine strong basic science focused on behavioral development with direct applications to management and conservation of large African carnivores, including those that are rare and endangered.