Lateral posture biases, habituation, and risk monitoring by wild ungulates

摘要

ABSTRACT In protected areas, wildlife may lose their fear of humans, and prey species may use human-disturbed areas to escape natural predators. Lateral bedding posture bias may reflect difference in monitoring and these changing patterns of risk stimuli. I studied wild elk in Banff and Jasper National Parks, Canada, where habituated animals enter into conflicts with humans, abandon migration, and negatively affect entire ecosystems. I recorded lateral bedding postures and lateral differences in detection distances when elk were approached. Elk had leftward posture biases when facing away from the herd toward the presumptive direction of potential predation, but had rightward biases when facing towards conspecifics. I found migratory elk had stronger lateral biases than elk residing year-round near humans. These results show lateral posture biases are context dependent on risk, and as these risks change, lateral biases change as well. These results provide important insights for the management of prey species subject to changing patterns of predation and human disturbance, and contribute to our growing understanding of the ecological implications of laterally in wild species.