A physiological perspective on nectar-feeding adaptation in phyllostomid bats.

Area of Science:

• Animal physiology
• Ecology
• Nutritional science

Background:

• Nectarivorous animals often increase food intake as nectar sugar concentration decreases.
• Physiological limitations can hinder energy acquisition from diluted nectar sources.
• Gut capacity is a potential factor influencing energy balance in nectar-feeding bats.

Purpose of the Study:

• To investigate the influence of gut capacity on energy acquisition and storage in nectar-feeding bats.
• To determine how different nectar sugar concentrations affect food intake and body mass changes in three bat species.
• To model the relationship between digestive traits and resource utilization in the field.

Main Methods:

• Measured food intake and body mass changes in three nectar-feeding bat species (Choeronycteris mexicana, Leptonycteris yerbabuenae, Glossophaga soricina).
• Bats were fed sucrose solutions across a range of concentrations (146–1,022 mmol L(-1)).
• Developed a model linking gut capacity to field-based food resource use.

Main Results:

• Species-specific differences in food intake and energy storage capacity were observed.
• Choeronycteris mexicana maintained constant energy intake and increased body mass across all tested concentrations.
• Glossophaga soricina and Leptonycteris yerbabuenae showed reduced sugar/energy intake and no body mass increase at low sugar concentrations.

Conclusions:

• Gut capacity significantly impacts how nectar-feeding bats manage energy intake and storage.
• Digestive traits play a crucial role in determining resource utilization strategies in these animals.
• The findings support the hypothesis that physiological traits mediate the use of environmental food resources.