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dc.contributor.authorRitchie, Mark E.en_US
dc.date.accessioned2006-09-11T19:23:16Z
dc.date.available2006-09-11T19:23:16Z
dc.date.issued1990-01en_US
dc.identifier.citationRitchie, Mark E.; (1990). "Optimal foraging and fitness in Columbian ground squirrels." Oecologia 82(1): 56-67. <http://hdl.handle.net/2027.42/47783>en_US
dc.identifier.issn0029-8549en_US
dc.identifier.issn1432-1939en_US
dc.identifier.urihttps://hdl.handle.net/2027.42/47783
dc.description.abstractOptimal diets were determined for each of 109 individual Columbian ground squirrels ( Spermophilus columbianus ) at two sites in northwestern Montana. Body mass, daily activity time, and vegetation consumption rates for individuals were measured in the field, along with the average water content of vegetation at each ground squirrel colony. I also measured stomach and caecal capacity and turnover rate of plant food through the digestive tract for individuals in the laboratory to construct regressions of digestive capacity as a function of individual body mass. Finally, I obtained literature estimates of average daily energy requirements as a function of body mass and digestible energy content of vegetation. These data were used to construct a linear programming diet model for each individual. The model for each individual was used to predict the proportion of two food types (monocots and dicots) that maximized daily energy intake, given time and digestive constraints on foraging. Individuals were classified as “optimal” or “deviating”, depending on whether their observed diet was significantly different from their predicted optimal diet. I determined the consequences of selecting an optimal diet for energy intake and fitness. As expected, daily energy intake calculated for deviators (based on their observed diet proportion) was less than that for optimal foragers. Deviating foragers do not appear to compensate for their lower calculated energy intake through other factors such as body size or physiological efficiency of processing food. Growth rate, yearly survivorship, and litter size increase with calculated energy intake, and optimal foragers have six times the reproductive success of deviators by age three. Optimal foraging behavior, therefore, appears to confer a considerable fitness advantage.en_US
dc.format.extent1476571 bytes
dc.format.extent3115 bytes
dc.format.mimetypeapplication/pdf
dc.format.mimetypetext/plain
dc.language.isoen_US
dc.publisherSpringer-Verlagen_US
dc.subject.otherFitnessen_US
dc.subject.otherPlant Sciencesen_US
dc.subject.otherEcologyen_US
dc.subject.otherEnergy Intakeen_US
dc.subject.otherGrowth Rateen_US
dc.subject.otherOptimal Foragingen_US
dc.subject.otherGround Squirrelsen_US
dc.subject.otherLife Sciencesen_US
dc.titleOptimal foraging and fitness in Columbian ground squirrelsen_US
dc.typeArticleen_US
dc.subject.hlbsecondlevelNatural Resources and Environmenten_US
dc.subject.hlbsecondlevelMolecular, Cellular and Developmental Biologyen_US
dc.subject.hlbsecondlevelEcology and Evolutionary Biologyen_US
dc.subject.hlbtoplevelHealth Sciencesen_US
dc.subject.hlbtoplevelScienceen_US
dc.description.peerreviewedPeer Revieweden_US
dc.contributor.affiliationumSchool of Natural Resources, University of Michigan, 48109-1115, Ann Arbor, MI, USA; Department of Ecology, Evolution and Behavior, University of Minnesota, 55455, Minneapolis, MN, USAen_US
dc.contributor.affiliationumcampusAnn Arboren_US
dc.description.bitstreamurlhttp://deepblue.lib.umich.edu/bitstream/2027.42/47783/1/442_2004_Article_BF00318534.pdfen_US
dc.identifier.doihttp://dx.doi.org/10.1007/BF00318534en_US
dc.identifier.sourceOecologiaen_US
dc.owningcollnameInterdisciplinary and Peer-Reviewed


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