Acceleration predicts energy expenditure in a fat, flightless, diving bird

Area of Science:

• Animal Ecology
• Bioenergetics
• Physiological Ecology

Background:

• Energy expenditure is crucial for animal behavior and life history.
• Measuring fine-scale energy use in wild animals is challenging.
• Accelerometry requires calibration for accurate energy expenditure estimation in free-living species.

Purpose of the Study:

• To calibrate accelerometry for estimating energy expenditure in Adélie penguins.
• To determine the most parsimonious models for wild energy expenditure estimation.
• To provide species-specific calibration equations for diverse behaviors.

Main Methods:

• Combined data from miniaturized acceleration loggers on 58 free-living Adélie penguins.
• Used doubly labeled water (DLW) to measure energy expenditure over several days.
• Analyzed dynamic body acceleration across terrestrial and aquatic behaviors.

Main Results:

• Dynamic body acceleration effectively predicted DLW-derived energy expenditure (R² = 0.72).
• A parsimonious model indicated different calibration coefficients for land and aquatic foraging (R² = 0.75).
• Reliable estimation of energy expenditure using accelerometry is feasible in penguins.

Conclusions:

• Accelerometry provides a reliable method for estimating energy expenditure in wild penguins.
• Developed calibration equations for predicting metabolic rate across various behaviors.
• Findings support the use of accelerometry in bioenergetic studies of marine predators.