Canadian Forest Service Publications
Space-use behaviour of woodland caribou based on a cognitive movement model. 2015. Avgar, T.; Baker, J.A.; Brown,G.S.; Hagens, J.S.; Kittle, A.M.; Mallon, E.E.; Mcgreer, M.T.; Mosser, A.; Newmaster, S.G.; Patterson, B.R.; Reid, D.E.B.; Rodgers, A.R.; Shuter, J.; Street, G.M.; Thompson, I.; Turetsky, M.J. Wiebe, P.A.;Fryxell, J.M. Journal of Animal Ecology 84:1059-1070.
Issued by: Great Lakes Forestry Centre
Catalog ID: 35992
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Movement patterns offer a rich source of information on animal behaviour and the ecological significance of landscape attributes. This is especially useful for species occupying remote landscapes where direct behavioural observations are limited. In this study, we fit a mechanistic model of animal cognition and movement to GPS positional data of woodland caribou (_Rangifer tarandus_ caribou; Gmelin 1788) collected over a wide range of ecological conditions. The model explicitly tracks individual animal informational state over space and time, with resulting parameter estimates that have direct cognitive and ecological meaning. Three biotic landscape attributes were hypothesized to motivate caribou movement: forage abundance (dietary digestible biomass), wolf (_Canis lupus_; Linnaeus, 1758) density and moose (_Alces alce_s; Linnaeus, 1758) habitat. Wolves are the main predator of caribou in this system and moose are their primary prey. Resulting parameter estimates clearly indicated that forage abundance is an important driver of caribou movement patterns, with predator and moose avoidance often having a strong effect, but not for all individuals. From the cognitive perspective, our results support the notion that caribou rely on limited sensory inputs from their surroundings, as well as on long-term spatial memory, to make informed movement decisions. Our study demonstrates how sensory, memory and motion capacities may interact with ecological fitness covariates to influence movement decisions by free-ranging animals.
Plain Language Summary
We studied the movement patterns of 60 adult female caribou fitted with GPS radio collars at each of two study areas in the boreal forests of northern Ontario. One area was commercially logged over the previous 50 years and the other was not. We expected caribou movements to be influenced by the search for nutrition and avoidance of predators. We found that forage abundance was the strongest influence. The avoidance of predators and moose (areas that are favourable to moose may attract more wolves and increase caribou predation risk) also had a strong effect on movement, but not for all individuals. We showed for the first time that caribou rely on sensory inputs from their surroundings as well as on long-term spatial memory to make informed decisions. This information improves our understanding of caribou behaviour.