Resting metabolic rate is repeatable, but does not affect call characteristics, in the gray treefrog Hyla...

Area of Science:

• Animal behavior
• Physiological ecology
• Evolutionary biology

Background:

• Consistent individual differences in behavior are common but their underlying mechanisms are poorly understood.
• Resting metabolic rate (RMR) is a potential driver of behavioral consistency due to its role in energy metabolism.
• Competing hypotheses exist regarding the relationship between RMR and behavioral expression.

Purpose of the Study:

• To investigate the relationship between RMR and energetically costly sexual signals in male Cope's grey treefrogs (Hyla chrysoscelis).
• To determine if RMR is repeatable within individuals over time.
• To assess if RMR consistency changes throughout the breeding season.

Main Methods:

• Recorded acoustic advertisement calls of individual male H. chrysoscelis in the field.
• Measured RMR of males the day after call recording.
• Repeated RMR measurements across multiple captures to assess repeatability and consistency over time.

Main Results:

• RMR was significantly repeatable within individuals.
• No evidence was found that RMR affected male advertisement call characteristics.
• RMR showed a decrease across the breeding season, reducing measurement consistency over time.

Conclusions:

• Calling behavior in H. chrysoscelis does not appear to signal male RMR to potential mates or rivals.
• While RMR itself is repeatable, its seasonal decline affects its consistency.
• Other metabolic factors may still contribute to individual variation in calling behavior.