Intersexual differences in density-dependent dispersal and their evolutionary drivers

Area of Science:

• Ecology
• Evolutionary Biology
• Behavioral Ecology

Background:

• Dispersal is a key evolutionary driver, but often studied without considering sex-specific differences.
• Dispersal ability is a life-history trait that can evolve under various pressures.
• Few studies investigate how environmental drivers differentially affect male and female dispersal.

Purpose of the Study:

• To investigate sex-specific differences in density-dependent emigration in a butterfly metapopulation.
• To understand how reproductive strategies influence dispersal patterns in males and females.

Main Methods:

• Utilized a metapopulation of Maculinea (Phengaris) teleius butterflies.
• Conducted intensive mark-release-recapture surveys.
• Analyzed dispersal parameters using the Virtual Migration model and multi-state recapture models.

Main Results:

• Male emigration rates were higher early in the season, especially in smaller patches.
• Male emigration decreased as the season progressed and female proportion increased.
• Female emigration increased later in the season, linked to reducing offspring competition.

Conclusions:

• Reproductive strategies significantly impact dispersal in both male and female butterflies.
• Sex-biased dispersal varies seasonally, driven by differing reproductive roles.
• These findings have crucial implications for understanding metapopulation functioning and evolution.