Individual and sex-specific differences in intrinsic growth rate covary with consistent individual differences in...

Area of Science:

• Behavioral Ecology
• Evolutionary Biology
• Animal Behavior

Background:

• Consistent individual differences in behavior (animal personality) are debated.
• A hypothesis links life-history productivity to behavioral traits like boldness and voracity.
• It's unclear if these profiles are fixed early or flexible due to environmental factors.

Purpose of the Study:

• To investigate the relationship between consistent individual differences in behavior and life-history productivity.
• To determine if bold and active crayfish exhibit higher growth rates.
• To test the personality-productivity hypothesis in a controlled, resource-rich environment.

Main Methods:

• Longitudinal study of 90 individually housed crayfish (Cherax destructor) over 4 months.
• Repeated measurements of mass, boldness (day and night), and voracity.
• Ad libitum feeding to isolate intrinsic growth capacity.

Main Results:

• Consistently bold crayfish showed higher voracity and maintained faster growth rates.
• Boldness measured during the day predicted boldness at night.
• Males were generally faster-growing, bolder, and more voracious than females.

Conclusions:

• The association between bold behavior and fast growth exists even without a direct link to resource acquisition.
• Findings support the 'personality-productivity' hypothesis.
• Further research should explore these links across diverse environmental contexts.