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BODY SIZE, ENERGY USE, AND COMMUNITY STRUCTURE OF SMALL MAMMALS
Author(s) -
Ernest S. K. Morgan
Publication year - 2005
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.1890/03-3179
Subject(s) - community structure , ecology , distribution (mathematics) , biology , mammal , bergmann's rule , resource distribution , geography , resource allocation , mathematics , mathematical analysis , computer network , geodesy , computer science , latitude
Body size has long been hypothesized to play a major role in community structure and dynamics. Two general hypotheses exist for how resources are distributed among body sizes: (1) resources are equally available and uniformly utilized across body sizes and (2) resources are differentially available to organisms of different body sizes, resulting in a nonuniform or modal distribution. It has also been predicted that the distribution of body sizes of species in a community should reflect the underlying availability of resources, with the emergence of aggregations of species around specific body sizes. I examined the relationship between energy utilization, body size, and community structure in nine small‐mammal communities in North America. In all communities, energy use across body sizes was significantly different from uniform. In contrast, none of the nine species‐level body size distributions were significantly different from uniform. Cross‐site comparisons showed that, while the species‐level body size distribution did not vary significantly among sites, the utilization of energy across body sizes did. These results suggest that uniform energy utilization does not occur in small‐mammal communities and that the species‐level body size distribution of a community is not determined by resource utilization.