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Benson-Amram, S., Weldele, M. L., & Holekamp, K. E. (2013). A comparison of innovative problem-solving abilities between wild and captive spotted hyaenas, Crocuta crocuta. Animal Behaviour, 85(2), 349–356.
Abstract: Innovative problem solving enables individuals to deal with novel social and ecological challenges. However, our understanding of the importance of innovation for animals in their natural habitat is limited because experimental investigations of innovation have historically focused on captive animals. To determine how captivity affects innovation, and whether captive studies of animal innovation suffer from low external validity, we need experimental investigations of innovation in both wild and captive populations of the same species in diverse taxa. Here we inquired whether wild and captive spotted hyaenas differ in their ability to solve the same novel technical problem, and in the diversity of exploratory behaviours they exhibit when first interacting with the problem. Our results suggest that wild and captive populations show important differences in their innovative problem-solving abilities. Captive hyaenas were significantly more successful at solving the novel problem, and significantly more diverse in their initial exploratory behaviour, than were wild hyaenas. We were able to rule out hypotheses suggesting that these differences result from excess energy or time available to captive animals. We conclude that captive hyaenas were more successful because captive individuals were less neophobic and more exploratory than their wild counterparts. These results have important implications for our interpretation of studies on innovative problem solving in captive animals and aid our attempts to gain a broader understanding of the importance of innovation for animals in their natural habitat.
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Smith, J. E., Kolowski, J. M., Graham, K. E., Dawes, S. E., & Holekamp, K. E. (2008). Social and ecological determinants of fission-fusion dynamics in the spotted hyaena. Anim. Behav., 76(3), 619–636.
Abstract: Theory predicts that individuals living in fission-fusion societies, in which group members frequently change subgroups, should modify grouping patterns in response to varying social and environmental conditions. Spotted hyaenas, Crocuta crocuta, are long-lived carnivores that reside in permanent social groups called clans. Clans are complex, fission-fusion societies in which individual members travel, rest and forage in subgroups that frequently change composition. We studied two clans in Kenya to provide the first detailed description of fission-fusion dynamics in this species. Because social and ecological circumstances can influence the cohesiveness of animal societies, we evaluated the extent to which specific circumstances promote the formation of subgroups of various sizes. We found that cooperative defence of shared resources during interclan competition and protection from lions were cohesive forces that promoted formation of large subgroups. We also tested hypotheses suggesting factors limiting subgroup size. Mothers with small cubs avoided conspecifics, thereby reducing infanticide risk. Victims of aggression either reconciled fights or separated from former opponents to reduce the immediate costs of escalated aggression in the absence of food. As predicted by the ecological constraints hypothesis, hyaenas adjusted their grouping patterns over both short and long time scales in response to feeding competition. Crocuta were most gregarious during periods of abundant prey, joined clanmates at ephemeral kills in numbers that correlated with the energetic value of the prey and gained the most energy when foraging alone because cooperative hunting attracted numerous competitors. Overall, our findings indicate that resource limitation constrains grouping in this species.
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