Energetic inequivalence in eusocial insect colonies
1Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA. john.delong@yale.edu
Biology Letters
|March 4, 2011
Summary
The energetic equivalence rule suggests metabolic rate is independent of body size. This study found whole-colony metabolic rate positively scales with body size in eusocial insects, challenging the rule.
Area of Science:
- Ecology
- Physiology
- Allometry
Background:
- The energetic equivalence rule posits population metabolic rate is independent of average body size.
- Previous allometric studies yielded conflicting results regarding this rule.
- Direct measurements of whole-population metabolic rate have been lacking.
Purpose of the Study:
- To directly test the energetic equivalence rule using whole-colony metabolic rate measurements.
- To investigate the relationship between body size, individual metabolic rate, and population size in eusocial insects.
Main Methods:
- Direct measurement of whole-colony metabolic rate in eusocial insects.
- Allometric analysis of individual metabolic rates and population size relative to body size.
- Application of consumer-resource models to interpret findings.
Main Results:
- A positive scaling of whole-colony metabolic rate with body size was observed.
- Individual metabolic rates scaled more steeply with body size than predicted by laboratory studies.
- Population size was found to be independent of body size.
Conclusions:
- The energetic equivalence rule does not hold for whole-colony metabolic rate in eusocial insects.
- Observed colony-level metabolic scaling may result from altered individual metabolic scaling and body size-dependent mortality.
- Findings highlight the complexity of metabolic scaling in social organisms.
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