Early growth trajectories affect sexual responsiveness

Area of Science:

• Ecology
• Evolutionary Biology
• Animal Behavior

Background:

• Early life growth trajectories can impact long-term life-history traits in animals.
• The relationship between early development and individual behavioral variation is understudied.
• Understanding these links is crucial for predicting animal responses to environmental changes.

Purpose of the Study:

• To investigate how manipulated early growth rates affect sexual responsiveness in male three-spined sticklebacks.
• To explore associations between reproductive behavior, investment, and lifespan.
• To determine if perceived time stress influences these trade-offs.

Main Methods:

• Juvenile three-spined sticklebacks (Gasterosteus aculeatus) underwent brief temperature manipulations to stimulate compensatory growth, independent of food availability.
• Sexual responsiveness, reproductive ornament development, nest-building time, and lifespan were measured.
• The influence of time stress (time until breeding season) on these trade-offs was analyzed.

Main Results:

• Slower growth rates in early development led to quicker sexual responsiveness to females.
• Faster sexual responsiveness correlated with faster development of sexual ornaments and longer nest-building times.
• Males with higher sexual responsiveness exhibited shorter lifespans, even after accounting for growth rate.

Conclusions:

• Developmental perturbations in early life significantly influence mating behavior and longevity in three-spined sticklebacks.
• Trade-offs between reproduction and lifespan are modulated by developmental conditions and perceived time stress.
• These findings highlight the lasting impact of early life experiences on life-history strategies.