Adiposity signals predict vocal effort in Alston's singing mice

Area of Science:

• Animal behavior
• Physiology
• Bioacoustics

Background:

• Animal displays are often costly and linked to body condition.
• Little is known about how signal elaboration varies with natural condition.
• Few studies demonstrate a strong link between condition and display effort.

Purpose of the Study:

• To investigate the relationship between physiological condition and acoustic display in Alston's singing mouse (Scotinomys teguina).
• To understand how animals adjust signal effort based on their body condition.

Main Methods:

• Characterized physiological condition using measures of caloric nutrients and adiposity.
• Analyzed acoustic displays, focusing on song effort (rate and duration).
• Assessed plasma hormone levels, particularly leptin, as predictors of display effort.

Main Results:

• Two main axes of physiological variation were identified: short-term nutrient fluctuations and longer-term adiposity.
• Song effort, characterized by high display rates and longer songs, was strongly correlated with adiposity.
• Leptin levels were a significant predictor of song display effort.

Conclusions:

• Body condition, specifically adiposity and leptin levels, significantly influences the elaboration of acoustic signals in Alston's singing mouse.
• Hormonal signals like leptin may mediate the translation of physiological state into behavioral decisions across vertebrates.
• This study provides insights into how animals manage costly traits based on their somatic state.