title: Elucidating the significance of spatial memory on movement decisions by African savannah elephants using state-space models.
abstract: Spatial memory facilitates resource acquisition where resources are patchy, but how it influences movement behaviour of wide-ranging species remains to be resolved. We examined African elephant spatial memory reflected in movement decisions regarding access to perennial waterholes. State-space models of movement data revealed a rapid, highly directional movement behaviour almost exclusively associated with visiting perennial water. Behavioural change point (BCP) analyses demonstrated that these goal-oriented movements were initiated on average 4.59 km, and up to 49.97 km, from the visited waterhole, with the closest waterhole accessed 90% of the time. Distances of decision points increased when switching to different waterholes, during the dry season, or for female groups relative to males, while selection of the closest waterhole decreased when switching. Overall, our analyses indicated detailed spatial knowledge over large scales, enabling elephants to minimize travel distance through highly directional movement when accessing water. We discuss the likely cognitive and socioecological mechanisms driving these spatially precise movements that are most consistent with our findings. By applying modern analytic techniques to high-resolution movement data, this study illustrates emerging approaches for studying how cognition structures animal movement behaviour in different ecological and social contexts.
authors: Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523-1474, USA Department of Anthropology, University of California Davis, 328 Young Hall, One Shields Avenue, Davis, CA 95616, USA leopolansky@gmail.com.
authors: Leo
authors: L
authors: Polansky
authors: Etosha Ecological Institute, PO Box 6, Okaukuejo via Outjo, Namibia.
authors: Werner
authors: W
authors: Kilian
authors: Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523-1474, USA Save the Elephants, PO Box 54667, Nairobi, Kenya.
authors: George
authors: G
authors: Wittemyer
mesh_terms: D000818:Animals; D003657:Decision Making; D004606:Elephants / Q000502:physiology*; D005260:Female; D040362:Geographic Information Systems; D006624:Hippocampus / Q000502:physiology; D008297:Male; D008390:Markov Chains; D008954:Models, Biological; D009068:Movement; D009276:Namibia; D012621:Seasons; D065852:Spatial Memory
keywords: Loxodonta africana; cognitive map; hidden Markov model; movement behaviour; movement ecology