Déterminants comportementaux de l'expansion de l'aire de répartition d'une population de bisons

Authors: Merkle, Jerod
Advisor: Fortin, Daniel
Abstract: In this thesis, I develop a mechanistic understanding of patch-scale foraging behavior and its effects on animal distribution. I build patch selection models to test how past experience, group dynamics, and population density influence an animal’s decision to return to previously visited sites or explore. I parameterized models using an extensive data set on the movements of wild bison (Bison bison) and their expected mean intake rate of digestible energy of meadows within their range. Bison chose previously visited meadows more often than random while taking into account connectivity, distance, profitability, and size of available meadows. The probability of choosing a previously visited meadow also increased: 1) after visiting a meadow with a lower profitability than recent past experience, 2) when other group members also had previously visited the meadow, and 3) with decreasing population density. I also demonstrate that the decisions bison made had adaptive value as they resulted in the use of more profitable meadows than available options. Finally, I illustrate the emergent space use patterns of these behaviors by using simulation and by examining temporal dynamics in the space use of bison. In comparison to random movement, using memory to incorporate past experience into patch choice decisions resulted in restricted population distribution in simulated landscapes. Likewise, for bison, the area of space used by individuals and the population was smaller when individuals more strongly chose previously visited meadows. My findings suggest that site fidelity behavior is a strong evolutionary force shaping animal distribution. I conclude that efforts to forecast animal distribution, including range dynamics, must take into account site fidelity behavior based on an animal’s past experience as well as its interaction with memory, sociality, and density-dependent processes. This study provides a novel link between memory capabilities of animals, foraging ecology, sociality, density-dependence, and animal distribution.
Document Type: Thèse de doctorat
Issue Date: 2014
Open Access Date: 20 April 2018
Permalink: http://hdl.handle.net/20.500.11794/25513
Grantor: Université Laval
Collection:Thèses et mémoires

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