Optimal foraging and fitness in Columbian ground squirrels
dc.contributor.author | Ritchie, Mark E. | en_US |
dc.date.accessioned | 2006-09-11T19:23:16Z | |
dc.date.available | 2006-09-11T19:23:16Z | |
dc.date.issued | 1990-01 | en_US |
dc.identifier.citation | Ritchie, 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.issn | 0029-8549 | en_US |
dc.identifier.issn | 1432-1939 | en_US |
dc.identifier.uri | https://hdl.handle.net/2027.42/47783 | |
dc.description.abstract | Optimal 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.extent | 1476571 bytes | |
dc.format.extent | 3115 bytes | |
dc.format.mimetype | application/pdf | |
dc.format.mimetype | text/plain | |
dc.language.iso | en_US | |
dc.publisher | Springer-Verlag | en_US |
dc.subject.other | Fitness | en_US |
dc.subject.other | Plant Sciences | en_US |
dc.subject.other | Ecology | en_US |
dc.subject.other | Energy Intake | en_US |
dc.subject.other | Growth Rate | en_US |
dc.subject.other | Optimal Foraging | en_US |
dc.subject.other | Ground Squirrels | en_US |
dc.subject.other | Life Sciences | en_US |
dc.title | Optimal foraging and fitness in Columbian ground squirrels | en_US |
dc.type | Article | en_US |
dc.subject.hlbsecondlevel | Natural Resources and Environment | en_US |
dc.subject.hlbsecondlevel | Molecular, Cellular and Developmental Biology | en_US |
dc.subject.hlbsecondlevel | Ecology and Evolutionary Biology | en_US |
dc.subject.hlbtoplevel | Health Sciences | en_US |
dc.subject.hlbtoplevel | Science | en_US |
dc.description.peerreviewed | Peer Reviewed | en_US |
dc.contributor.affiliationum | School of Natural Resources, University of Michigan, 48109-1115, Ann Arbor, MI, USA; Department of Ecology, Evolution and Behavior, University of Minnesota, 55455, Minneapolis, MN, USA | en_US |
dc.contributor.affiliationumcampus | Ann Arbor | en_US |
dc.description.bitstreamurl | http://deepblue.lib.umich.edu/bitstream/2027.42/47783/1/442_2004_Article_BF00318534.pdf | en_US |
dc.identifier.doi | http://dx.doi.org/10.1007/BF00318534 | en_US |
dc.identifier.source | Oecologia | en_US |
dc.owningcollname | Interdisciplinary and Peer-Reviewed |
Files in this item
Remediation of Harmful Language
The University of Michigan Library aims to describe library materials in a way that respects the people and communities who create, use, and are represented in our collections. Report harmful or offensive language in catalog records, finding aids, or elsewhere in our collections anonymously through our metadata feedback form. More information at Remediation of Harmful Language.
Accessibility
If you are unable to use this file in its current format, please select the Contact Us link and we can modify it to make it more accessible to you.