The Offspring‐Size/Clutch‐Size Trade‐Off in Mammals
Open accessAbstract
The Smith-Fretwell model for optimal offspring size assumes the existence of an inverse proportional relationship (i.e., trade-off) between the number of offspring and the amount of resources invested in an individual offspring; virtually all of the many models derived from theirs make the same trade-off assumption. Over the last 30 years it has become apparent that the predicted proportionality is often not observed when evaluated across species. We develop a general allometric approach to correct for size-related differences in the resources available for reproduction. Using data on mammals, we demonstrate that the predicted inverse proportional relationship between number of offspring and offspring size is closely approached after correcting for allocation, though there is a slight curvature in the relationship. We discuss applications for this approach to other organisms, possible causes for the curvature, and the usefulness of allometries for estimating life-history variables that are difficult to measure.
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Increased energy throughput is associated with increased reproductive output within and among species.
“Both within (2) and among (3) species, increased energy throughput (i.e., calories consumed and expended per day) is associated with increased reproductive output (i.e., grams of offspring produced per year).”
From Metabolic adaptation for low energy throughput in orangutans. (2010) · cites this paper as [3]
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Research works printed but not linked: 1
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Metabolic adaptation for low energy throughput in orangutans.
Pontzer, H., Raichlen, D. A., Shumaker, R. W., Ocobock, C., & Wich, S. A. (2010) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1001031107 · Cited by 105 · see citing works
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- Authors
- Charnov, E. L., & Ernest, S. K. M.
- Affiliations
- University of New Mexico (US)
- Utah State University (US)
- ORCID
- Ernest, S. K. Morgan
- Venue
- The American Naturalist
- Publisher
- University of Chicago Press
- Published
- 2006-04
- Volume
- 167
- Issue
- 4
- Pages
- 578-582
- ISSN
- 0003-0147 (ISSN-L)
- 1537-5323
- OpenAlex
- W2086995370
- Cited by
- 123
- References
- 16
- Citations by year
- 2026: 1 · 2025: 8 · 2024: 6 · 2023: 1 · 2022: 9 · 2021: 4 · 2020: 12 · 2019: 9 · 2018: 6 · 2017: 6 · 2016: 5 · 2015: 8 · 2014: 5 · 2013: 4 · 2012: 6
- FWCI
- 7.76
- Type
- journal article
- Language
- en
- Open access
- Locations
- The American Naturalist (publishedVersion)
- PubMed (publishedVersion)
- Digital Commons - USU (Utah State University) (submittedVersion)
- UNM’s Digital Repository (University of New Mexico) (submittedVersion)
- Topics
- Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Animal Behavior and Reproduction
- Physical Sciences › Earth and Planetary Sciences › Paleontology › Evolution and Paleontology Studies
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Evolutionary Psychology and Human Behavior
- Keywords
- offspring size, clutch size, offspring number, resource allocation, allometry, life-history trade-offs, mammals, reproductive investment
- MeSH terms
- Animals, Litter Size, Mammals, Body Size
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