Density fluctuations represent a key process maintaining personality variation in a wild passerine bird

Area of Science:

• Behavioral Ecology
• Evolutionary Biology
• Animal Behavior

Background:

• Heritable personality variation is common in animals but its maintenance under fluctuating selection remains unclear.
• Spatiotemporal variation in conspecific density is a potential driver of fluctuating selection.
• Understanding this dynamic is crucial for explaining persistent personality differences in wild populations.

Discussion:

• Great tits (Parus major) exhibited viability selection on exploratory behavior that varied with local density.
• Faster explorers were favored at low densities, while slower explorers were favored at high densities.
• This density-dependent selection was primarily driven by temporal fluctuations in local density.

Key Insights:

• Spatiotemporal variation in conspecific density is a key factor driving fluctuating selection on personality traits.
• Great tits did not demonstrate adaptive density-dependent plasticity in their exploratory behavior.
• The interplay between fluctuating selection and a lack of adaptive plasticity maintains animal personality variation.

Outlook:

• Further research could explore other ecological factors influencing fluctuating selection on animal personality.
• Investigating the genetic basis of behavioral plasticity in response to density is warranted.
• This study provides a framework for understanding personality maintenance in dynamic environments.