Evolution of condition-dependent dispersal under kin competition

Area of Science:

• Ecology
• Evolutionary Biology
• Behavioral Ecology

Background:

• Dispersal patterns often correlate with individual body condition.
• The social dominance hypothesis explains weak individual dispersal, but strong individual dispersal remains less understood.
• Understanding dispersal drivers is crucial for population dynamics and conservation.

Purpose of the Study:

• To model the relationship between an individual's body condition and its propensity to disperse.
• To investigate the fitness consequences of dispersal versus site retention in a patchy environment.
• To explore the evolutionary stable strategies for dispersal under varying competitive scenarios.

Main Methods:

• Developed a mathematical model based on kin competition principles (Hamilton and May).
• Incorporated body condition as a determinant of competitive ability and dispersal propensity.
• Analyzed dispersal strategies in an annual species inhabiting a patchy environment with variable patch qualities.

Main Results:

• The model suggests that dispersal of strong individuals can be a common outcome.
• In most scenarios, the evolutionarily stable dispersal probability increases with body condition.
• A non-monotone relationship was found where very weak and very strong individuals disperse most, while intermediate individuals do not.

Conclusions:

• Body condition is a significant factor influencing dispersal decisions.
• The evolutionarily stable dispersal strategy can be complex, not always favoring weaker individuals.
• Environmental patchiness and competition dynamics shape the evolution of dispersal in populations.