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Animal response to nested self‐similar patches: a test with woolly bears
Author(s) -
McClure Mark F.,
Shipley Lisa A.
Publication year - 2009
Publication title -
oikos
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.672
H-Index - 179
eISSN - 1600-0706
pISSN - 0030-1299
DOI - 10.1111/j.1600-0706.2008.17117.x
Subject(s) - foraging , scaling , partition (number theory) , ecology , null model , resource distribution , multidimensional scaling , home range , resource (disambiguation) , optimal foraging theory , spatial distribution , biological system , mathematics , biology , computer science , statistics , resource allocation , habitat , geometry , computer network , combinatorics
To gain insight into how animals respond to resource patchiness at different spatial scales, we envision their responses in environments comprised of nested, self‐similar patches. In these environments, all resources reside within the smallest patches, and resource density declines as a constant exponent of patch size. Accordingly, we use simple mathematical formulations to describe a self‐similar environment and a null model of how animals should respond to this environment if they do not perceive resource distribution. We then argue that animals that can perceive resource distribution should partition space by reducing the relative time searching between patches as patch size increases. On an experimental landscape, we found that woolly bear caterpillars Grammia geneura could partition space in this manner, but the range of patch sizes over which they did so tended to increase with resource aggregation. Nevertheless, scaling efficiency (i.e. the scaling of search time versus the scaling or resource density) was similar in all distributions when averaged over all patch sizes. These disparate patterns with similar outcomes resulted from differences in caterpillars’ abilities to discriminate spatially among patches of different sizes via their movement pathways, and differences in their use of speed to detect resource items. Our work is relevant to the characterization of resource availability from an animal's perspective, and to the linking of optimal foraging theory to the modeling of search behavior.