Escape from predators and genetic variance in birds

Area of Science:

• Evolutionary biology
• Behavioral ecology
• Conservation genetics

Background:

• Predation is a major driver of mortality, leading to evolved antipredator defenses.
• Antipredator behaviors, such as flight initiation distance (FID), reflect a trade-off between predation risk and foraging benefits.
• Genetic factors influence the evolution and expression of antipredator defenses.

Purpose of the Study:

• To investigate the relationship between genetic variation and antipredator behavior in birds.
• To determine if flight initiation distance (FID) is correlated with measures of genetic diversity.

Main Methods:

• Analyzed FID in 128 bird species.
• Assessed genetic variation using band sharing coefficients (minisatellites), observed heterozygosity, and inbreeding coefficients (microsatellites).
• Employed phylogenetic analyses controlling for confounding variables.

Main Results:

• Shorter FID was associated with higher band sharing coefficients, lower heterozygosity, and higher inbreeding coefficients.
• These correlations held after controlling for body size and other factors.
• Phylogenetic analyses confirmed the link between reduced genetic variation and diminished antipredator behavior.

Conclusions:

• Antipredator behavior in birds is significantly influenced by genetic variance.
• Threatened species with low genetic diversity may exhibit reduced antipredator responses.
• This could exacerbate population declines due to predation pressure.