Highlighting when animals expend excessive energy for travel using dynamic body acceleration

Area of Science:

• Animal physiology
• Biomechanics
• Marine biology

Background:

• Animal movement incurs significant energetic costs, driving selection for efficient locomotion.
• Deviations from minimum energy expenditure suggest important ecological or behavioral drivers.

Purpose of the Study:

• To introduce a novel metric, proxy for power above minimum (PPAmin), to quantify energy expenditure exceeding minimum requirements during animal movement.
• To apply this metric to whale sharks (Rhincodon typus) to understand their energetic strategies.

Main Methods:

• Utilized Dynamic Body Acceleration (DBA) as a proxy for movement-based power.
• Measured vertical velocity (rate of change in depth).
• Derived minimum power requirements for swimming at defined vertical velocities and calculated PPAmin by subtracting DBA from estimated minimum power.

Main Results:

• The PPAmin metric successfully identified instances where whale sharks traveled above their estimated minimum energetic thresholds.
• This highlights periods of potentially significant behavioral or environmental influences on energy expenditure.

Conclusions:

• The PPAmin metric offers a valuable tool for comparative studies across species to identify conditions prompting deviations from energy-efficient travel.
• Understanding these deviations can provide insights into critical ecological factors influencing animal behavior and energetics.