Conspicuous Plumage Does Not Increase Predation Risk: A Continent-Wide Test Using Model Songbirds

Area of Science:

• Evolutionary biology
• Behavioral ecology
• Ornithology

Background:

• Female plumage coloration is shaped by various evolutionary forces, with predation risk being a significant but understudied factor.
• Conspicuous coloration may offer benefits but also incur costs, such as increased predation, particularly in open habitats.

Purpose of the Study:

• To investigate the relationship between female plumage coloration and predation risk in Australian fairy-wrens.
• To test the hypothesis that conspicuous female coloration increases vulnerability to predators in open habitats.

Main Methods:

• Utilized 3-D-printed models of male and female fairy-wrens with varying plumage coloration (conspicuous and dull).
• Measured predation attempt rates on these models across eight diverse Australian fairy-wren habitats.
• Analyzed attack rates in relation to habitat openness, latitude, and plumage contrast with the environment.

Main Results:

• Predation rates were higher in open habitats and at higher latitudes.
• Contrary to predictions, dull female models were attacked at similar rates to conspicuous female models.
• Female models experienced increased attack probability in open habitats compared to conspicuous male models; plumage contrast was not a significant factor.

Conclusions:

• The hypothesis that conspicuous plumage alone increases predation cost is not supported by this study.
• Plumage conspicuousness likely interacts with other ecological factors, rather than acting in isolation, to drive the evolution of coloration in female birds.