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Does predation select for or against avian coloniality? A comparative analysis
S A M Varela1, E Danchin, R H Wagner
1Laboratoire du Fonctionnement et Evolution des Systèmes Ecologiques, Université Pierre et Marie Curie, CNRS - UMR 7625, Paris, France. varcela@cict.fr
Journal of Evolutionary Biology
|June 23, 2007
Summary
Coloniality in birds does not always reduce predation risk. This study found that colonial nesting may attract predators, increasing vulnerability, rather than providing safety for bird species.
Area of Science:
- Evolutionary Biology
- Ornithology
- Behavioral Ecology
Background:
- Predation is a key factor influencing the evolution of animal behavior.
- Coloniality in birds is a widespread breeding strategy with debated anti-predation benefits.
- Some evidence suggests colonies attract predators, while others propose they offer protection.
Purpose of the Study:
- To test the reduced predation hypothesis (coloniality as protection) versus the increased predation hypothesis (coloniality as a risk).
- To investigate the evolutionary relationship between colonial breeding and predation vulnerability in birds.
- To determine if coloniality primarily deters or attracts predators.
Main Methods:
- Comparative analysis of 363 species within the avian order Ciconiiformes.
- Utilized Pagel's general method for discrete variable comparative analysis.
- Assessed species' predation vulnerability based on nest location and physical characteristics.
Main Results:
- A correlation between coloniality and predation vulnerability was confirmed.
- The reduced predation hypothesis predictions were not supported.
- The increased predation hypothesis predictions were supported, indicating coloniality can increase risk.
Conclusions:
- Colonial breeding in Ciconiiformes does not consistently offer protection from predators.
- The evolution of coloniality may be linked to increased, not decreased, predation risk.
- Species that are both colonial and vulnerable face significant predation pressure.
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