Does competition allow male mate choosiness in threespine sticklebacks?

Area of Science:

• Evolutionary biology
• Behavioral ecology
• Animal behavior

Background:

• Mate choice theories suggest competition influences mate preferences.
• Understanding how competition affects choosiness is key to explaining mating system variation.

Purpose of the Study:

• To investigate how intensified male competition affects mate choice decisions in threespine stickleback males.
• To determine if male condition influences choosiness under varying levels of competition.

Main Methods:

• Manipulated operational sex ratio to create varying levels of male competition.
• Presented threespine stickleback males with sequential female choices.
• Assessed male choosiness based on female size and male condition.

Main Results:

• Males were choosy regardless of condition when competition was low.
• In high-competition settings, poor-condition males became indiscriminate, while good-condition males remained selective.
• Competition induced condition-dependent mate choosiness.

Conclusions:

• Male competition can lead to condition-dependent mate preferences.
• The cost of choice varies with male condition and competition intensity.
• This variation may explain the persistence of male mate choosiness in competitive populations.