Sex-specific trade-offs influence thermoregulation under climate change

Area of Science:

• Ecology and evolutionary biology
• Climate change biology
• Animal behavior

Background:

• Climate change is increasing thermal stress on species globally.
• Behavioral thermoregulation is crucial for animals to avoid heat stress.
• Individual traits, like sex and reproductive status, can influence heat sensitivity and behavioral responses.

Purpose of the Study:

• To investigate how sex and reproductive status affect thermoregulatory behavior in moose (Alces alces).
• To determine the efficacy of selected thermal refuges in mitigating overheating risk.
• To identify sex-specific trade-offs in behavioral thermoregulation under thermal stress.

Main Methods:

• Assessed thermal refuge selection at moose bed sites.
• Developed biophysical models to evaluate the effectiveness of refuge selection.
• Compared behavioral responses between sexes and reproductive statuses.

Main Results:

• Reproductive status did not influence thermal refuge selection in females.
• Sexes differed in refuge selection: females prioritized canopy cover and wind avoidance, while males did not prioritize cover and showed weaker wind avoidance.
• Both sexes were more likely to overheat in low-cover areas, irrespective of wind speed; males exhibited weaker refuge selection despite higher overheating risk.

Conclusions:

• Moose exhibit sex-specific thermoregulatory trade-offs, with males demonstrating less optimal behavior.
• Life history trade-offs do not fully explain the observed sub-optimal thermoregulation in males.
• Trait-based approaches are vital for understanding ecosystem responses to climate change, highlighting differential impacts on demographic groups.