Validating accelerometry estimates of energy expenditure across behaviours using heart rate data in a free-living seabird

Hicks, Olivia, Burthe, Sarah, Daunt, Francis, Butler, Adam, Bishop, Charles and Green, Jonathan A ORCID: 0000-0001-8692-0163 (2017) Validating accelerometry estimates of energy expenditure across behaviours using heart rate data in a free-living seabird JOURNAL OF EXPERIMENTAL BIOLOGY, 220 (10). pp. 1875-1881. ISSN 0022-0949, 1477-9145

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Abstract

Twomain techniques have dominated the field of ecological energetics: the heart rate and doubly labelled water methods. Although well established, they are not without their weaknesses, namely expense, intrusivenessandlackof temporal resolution.Anewtechniquehas been developed using accelerometers; it uses the overall dynamic body acceleration (ODBA) of an animal as a calibrated proxy for energy expenditure. This method provides high-resolution data without the need for surgery. Significant relationships exist between the rate of oxygen consumption (VO<inf>2</inf>) and ODBA in controlled conditions across a number of taxa; however, it is not known whether ODBA represents a robust proxy forenergyexpenditure consistently inallnaturalbehaviours and there have been specific questions over its validity during diving, in diving endotherms. Here, we simultaneously deployed accelerometers and heart rate loggers in a wild population of European shags (Phalacrocorax aristotelis). Existing calibration relationships were then used to make behaviour-specific estimates of energy expenditure for each of these two techniques. Compared with heart rate-derived estimates, the ODBA method predicts energy expenditure well during flight and diving behaviour, but overestimates the cost of resting behaviour. We then combined these two datasets to generate a new calibration relationship between ODBA and VO<inf>2</inf> that accounts for this by being informed by heart rate-derived estimates. Across behaviours we found a good relationship between ODBA and VO<inf>2</inf>. Within individual behaviours, we found useable relationships between ODBA and VO<inf>2</inf> for flight and resting, and a poor relationship during diving. The error associated with these new calibration relationships mostly originates from the previous heart rate calibration rather than the error associated with the ODBA method. The equations provide tools for understanding how energy constrains ecology across the complex behaviour of free-living diving birds.

Item Type:	Article
Uncontrolled Keywords:	Dynamic body acceleration, Field metabolic rate, Diving, Flying, Shag, Phalacrocorax aristotelis
Depositing User:	Symplectic Admin
Date Deposited:	24 May 2017 14:00
Last Modified:	22 May 2026 22:13
DOI:	10.1242/jeb.152710
Related Websites:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3007641
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