Age-specific mating strategies and reproductive senescence

Area of Science:

• Evolutionary Biology
• Behavioral Ecology
• Reproductive Strategies

Background:

• Female polyandry (mating with multiple males) is a widespread reproductive strategy, yet its evolutionary drivers remain debated.
• Hypotheses suggest females gain indirect benefits, such as increased offspring quality, by mating with superior males.
• Age-related changes in male and female quality can influence mating decisions and reproductive success.

Purpose of the Study:

• To investigate the role of age-related variation in male and female quality on mating strategies in the common lizard (Lacerta vivipara).
• To test the hypothesis that females engage in polyandry to secure mating with high-quality males.
• To determine if polyandry in this species is driven by sexual conflict or by female choice for male quality.

Main Methods:

• Utilized the common lizard (Lacerta vivipara) as a model organism with natural variation in age and reproductive value.
• Assessed age-related performance and reproductive success in both males and females.
• Analyzed mating strategies (polygyny vs. polyandry) in relation to age and offspring viability.

Main Results:

• Male reproductive success and offspring viability varied with age, with intermediate-aged males showing the highest quality.
• Males at their peak performance adopted polygyny, siring more viable offspring.
• Females at their peak performance were less polyandrous, while younger and older females increased their mating frequency (polyandry) to enhance fitness.

Conclusions:

• Polyandry in female common lizards appears to be a strategy to seek out high-quality, intermediate-aged males, particularly for younger and older females.
• Mating with intermediate-aged males, regardless of female strategy, resulted in higher offspring viability.
• The observed positive correlation between male and female fitness through mating suggests polyandry is not driven by sexual conflict in this species.