Temperature change exerts sex-specific effects on behavioural variation

Area of Science:

• Behavioral Ecology
• Physiological Ecology
• Evolutionary Biology

Background:

• Temperature significantly influences organismal fitness and ecological interactions.
• While mean temperature effects on ectotherm behavior are known, individual-level variation and sex differences remain poorly understood.
• Individual behavioral variation is crucial as natural selection acts at this level.

Purpose of the Study:

• To investigate how temperature affects individual-level behavioral variation and metabolism in male and female *Drosophila melanogaster*.
• To determine if sex differences exist in thermal plasticity of behavior and metabolism.
• To explore the ecological and evolutionary consequences of temperature-induced behavioral variation.

Main Methods:

• Repeated measures of locomotor activity and metabolic rate were taken from adult male and female *Drosophila melanogaster* (n=129).
• Measurements were conducted at two temperatures: a standard 25°C and a high 28°C.
• Statistical analyses were performed to compare responses between sexes and temperatures.

Main Results:

• Males exhibited greater responsiveness in mean activity levels to temperature change compared to females.
• No significant sex differences were found in the thermal plasticity of standard or active metabolic rates.
• Increased temperatures amplified both among- and within-individual variation in male locomotor activity, but not in females.

Conclusions:

• Sex differences in behavioral responses to temperature may have significant ecological and evolutionary implications.
• Males show increased behavioral variation at higher temperatures, suggesting potential sex-specific vulnerabilities to climate warming.
• Further research is needed to understand the population-level consequences of these sex-specific thermal responses.