Female in-nest chatter song increases predation

Area of Science:

• Animal Behavior
• Evolutionary Biology
• Ornithology

Background:

• Female song is an ancestral trait in songbirds, but females often sing less than males.
• The reasons for reduced female singing, particularly predation costs, are not fully understood.

Purpose of the Study:

• To investigate sex differences in the predation costs associated with singing behavior in the superb fairy-wren (Malurus cyaneus).
• To determine if singing rate correlates with predation risk for nesting birds.

Main Methods:

• Observed singing rates and proximity to the nest for both male and female superb fairy-wrens throughout the breeding cycle.
• Correlated singing behavior with observed rates of egg and nestling predation.

Main Results:

• Both sexes reduced singing during incubation and chick-feeding stages compared to the fertile period.
• Females sang more frequently near or inside the nest compared to males.
• Female singing rate, but not male singing rate, predicted higher rates of egg and nestling predation.

Conclusions:

• Singing behavior incurs a significant predation risk, especially for parent birds attending offspring at the nest.
• Differences in parental care roles and nest proximity explain observed sex differences in singing rates and associated predation costs in superb fairy-wrens.