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The relationship between body size and population abundance in animals
1Peter Cotgreave is at the Laboratoire de Biométrie Génétique et Biologie des Populations, URA-CNRS 243, Université Claude Bernard - Lyon 1, 43 boulevard du 11 novembre 1918, 69622 Villeurbanne Cedex, France.
Trends in Ecology & Evolution
|January 18, 2011
Summary
Species body size influences population density, with larger species typically found at lower densities. This relationship is complex and varies within ecological communities, suggesting factors beyond energy use shape abundance patterns.
Area of Science:
- Ecology
- Zoology
- Population Biology
Background:
- Ecological theory posits that population density is inversely related to body size.
- Early hypotheses suggested energy-independent scaling of population energy use across body sizes.
- Recent research indicates this relationship is not universal across local communities.
Purpose of the Study:
- To investigate the variability of body size-density relationships within local ecological communities.
- To explore the influence of energetic constraints and ecological processes on species abundance patterns.
Main Methods:
- Analysis of existing ecological data on species body size and population density.
- Examination of patterns across different taxonomic and ecological groups within communities.
- Assessment of the role of energetic equivalence and interspecific competition.
Main Results:
- Population density generally decreases with increasing body size, but this pattern is highly variable.
- The body size-density relationship differs significantly across various subsets of ecological communities.
- Energetic considerations appear more relevant for abundant species, while competition may structure densities of less common species.
Conclusions:
- The relationship between body size and population density is not a simple universal rule.
- Ecological context, including taxonomic group and community structure, significantly modifies this relationship.
- Both energetic factors and ecological processes like competition play roles in determining species abundance patterns.
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