Improving the precision and accuracy for estimating energy expenditure using the heart rate method

Area of Science:

• Animal physiology
• Ecological energetics
• Bioenergetics

Background:

• The heart rate technique is widely used to estimate oxygen consumption (Vo2) and energy expenditure in free-ranging animals.
• A key limitation is interindividual variability in the heart rate (f(H)) to Vo2 relationship, leading to estimation errors.

Purpose of the Study:

• To develop a novel analysis technique to improve the accuracy and precision of Vo2 estimation using heart rate.
• To address the challenge of interindividual variability in f(H)-Vo2 relationships.

Main Methods:

• Developed a new analysis technique based on parallel f(H)/Vo2 relationships that differ in elevation.
• Applied the technique to estimate Vo2 in macaroni penguins.

Main Results:

• The new technique significantly reduced the coefficient of variability for individual Vo2 estimates from 18% to 9%.
• Demonstrated superior accuracy and precision compared to traditional methods.

Conclusions:

• The novel analysis technique enhances the reliability of the heart rate method for assessing individual animal energetics.
• Enables more accurate deduction of energetic strategies in free-ranging animals.