PARENT SESSION
Oral Session # 42: Mammal Ecology: From Mice to Elephants.
Presiding: H Howe
Wednesday, August 6. 8:00 AM to 11:30 AM, SITCC Meeting Room 104.
Does foraging behavior contribute to sexual segregation in bison across all hierarchical scales?
Kerby, Jay*,1, Engle, David1, Fuhlendorf, Samuel1, 1 Department of Plant and Soil Sciences, Stillwater, OK, USA
ABSTRACT- Many species of large ungulates are known to exhibit sexual segregation. This segregation is expressed at multiple hierarchical levels (i.e. landscapes, patches, and plants). North American Bison (Bos bison) exhibit sexual segregation in foraging behavior in their diet and within landscapes. Mature male bison select a diet with higher proportions of warm-season grasses than do mature female bison. Mature male bison also form independent groups that preferentially utilize undisturbed habitats, but mature female bison in mixed groups preferentially utilize recently disturbed habitats. Little is known about the foraging behavior of bison within patches and what role that behavior plays in sexual segregation. Therefore, the objective of our study was to investigate the foraging behavior of bison in heterogeneous patches created by a fire-grazing interaction. We describe attributes of foraging paths of bison in multiple vegetation patches with contrasting structure and composition through 3 seasons. Mature female bison adjust foraging paths in response to differences in vegetation structure and composition among patch types and seasons. Mature male bison are generally unresponsive to changes in vegetation structure and composition among patches and seasons. These results show that bison exhibit patch-level segregation. This segregation may result from contrasting nutritional requirements of mature female and male bison. Differences in social dynamics of male groups and mixed groups that include mature female bison may also explain segregation of foraging behavior.
Key words: Foraging paths, Ecological hierarchy, Landscape heterogeneity, Sexual segregation