Accelerometers can measure total and activity-specific energy expenditures in free-ranging marine mammals only if linked to time-activity budgets

Tiphaine Jeanniard-du-Dot, Christophe Guinet, John P. Y. Arnould, John R. Speakman, Andrew Trites

Research output: Contribution to journalArticle

22 Citations (Scopus)
6 Downloads (Pure)

Abstract

1-Energy expenditure is an important component of foraging ecology, but is extremely difficult to estimate in free-ranging animals and depends on how animals partition their time between different activities during foraging. Acceleration data has emerged as a new way to determine energy expenditure at a fine scale but needs to be tested and validated in wild animals. 2-This study investigated whether vectorial dynamic body acceleration (VeDBA) could accurately predict the energy expended by marine predators during a full foraging trip. We also aimed to determine whether the accuracy of predictions of energy expenditure derived from acceleration increased when partitioned by different types of at-sea activities (i.e., diving, transiting, resting and surface activities) vs calculated activity-specific metabolic rates. 3-To do so, we equipped 20 lactating northern (Callorhinus ursinus) and 20 Antarctic fur seals (Arctocephalus gazella) with GPS, time-depth recorders and tri-axial accelerometers, and obtained estimates of field metabolic rates using the doubly-labelled water (DLW) method. VeDBA was derived from tri-axial acceleration, and at-sea activities (diving, transiting, resting and surface activities) were determined using dive depth, tri-axial acceleration and traveling speed. 4-We found that VeDBA did not accurately predict the total energy expended by fur seals during their full foraging trips (R2 = 0.36). However, the accuracy of VeDBA as a predictor of total energy expenditure increased significantly when foraging trips were partitioned by activity and used activity-specific VeDBA paired with time activity budgets (R2 = 0.70). Activity-specific VeDBA also accurately predicted the energy expenditures of each activity independent of each other (R2 > 0.85). 5-Our study confirms that acceleration is a promising way to estimate energy expenditures of free-ranging marine mammals at a fine scale never attained before. However, it shows that it needs to be based on the time-activity budget that make up foraging trips rather than being derived as a single measure of VeDBA applied to entire foraging trips. Our activity-based method provides a cost-effective means to accurately calculate energy expenditures of fur seals using acceleration and time-activity budgets, a stepping stone for numerous other research fields.
Original languageEnglish
Pages (from-to)377–386
Number of pages10
JournalFunctional Ecology
Volume31
Issue number2
Early online date3 Oct 2016
DOIs
Publication statusPublished - 1 Feb 2017

Fingerprint

specific energy
accelerometer
marine mammal
marine mammals
activity pattern
energy expenditure
expenditure
energy
foraging
seals
fur
diving
Callorhinus
Arctocephalus
Gazella
animal
animals

Keywords

  • acceleration
  • VeDBA
  • time-activity budget
  • northern fur seal
  • Antarctic fur seal
  • energy expenditure
  • metabolic rate
  • foraging

Cite this

Accelerometers can measure total and activity-specific energy expenditures in free-ranging marine mammals only if linked to time-activity budgets. / Jeanniard-du-Dot, Tiphaine; Guinet, Christophe; Arnould, John P. Y.; Speakman, John R.; Trites, Andrew.

In: Functional Ecology, Vol. 31, No. 2, 01.02.2017, p. 377–386 .

Research output: Contribution to journalArticle

Jeanniard-du-Dot, Tiphaine ; Guinet, Christophe ; Arnould, John P. Y. ; Speakman, John R. ; Trites, Andrew. / Accelerometers can measure total and activity-specific energy expenditures in free-ranging marine mammals only if linked to time-activity budgets. In: Functional Ecology. 2017 ; Vol. 31, No. 2. pp. 377–386 .
@article{37ba5180d496495e8f4a3f735a64e583,
title = "Accelerometers can measure total and activity-specific energy expenditures in free-ranging marine mammals only if linked to time-activity budgets",
abstract = "1-Energy expenditure is an important component of foraging ecology, but is extremely difficult to estimate in free-ranging animals and depends on how animals partition their time between different activities during foraging. Acceleration data has emerged as a new way to determine energy expenditure at a fine scale but needs to be tested and validated in wild animals. 2-This study investigated whether vectorial dynamic body acceleration (VeDBA) could accurately predict the energy expended by marine predators during a full foraging trip. We also aimed to determine whether the accuracy of predictions of energy expenditure derived from acceleration increased when partitioned by different types of at-sea activities (i.e., diving, transiting, resting and surface activities) vs calculated activity-specific metabolic rates. 3-To do so, we equipped 20 lactating northern (Callorhinus ursinus) and 20 Antarctic fur seals (Arctocephalus gazella) with GPS, time-depth recorders and tri-axial accelerometers, and obtained estimates of field metabolic rates using the doubly-labelled water (DLW) method. VeDBA was derived from tri-axial acceleration, and at-sea activities (diving, transiting, resting and surface activities) were determined using dive depth, tri-axial acceleration and traveling speed. 4-We found that VeDBA did not accurately predict the total energy expended by fur seals during their full foraging trips (R2 = 0.36). However, the accuracy of VeDBA as a predictor of total energy expenditure increased significantly when foraging trips were partitioned by activity and used activity-specific VeDBA paired with time activity budgets (R2 = 0.70). Activity-specific VeDBA also accurately predicted the energy expenditures of each activity independent of each other (R2 > 0.85). 5-Our study confirms that acceleration is a promising way to estimate energy expenditures of free-ranging marine mammals at a fine scale never attained before. However, it shows that it needs to be based on the time-activity budget that make up foraging trips rather than being derived as a single measure of VeDBA applied to entire foraging trips. Our activity-based method provides a cost-effective means to accurately calculate energy expenditures of fur seals using acceleration and time-activity budgets, a stepping stone for numerous other research fields.",
keywords = "acceleration, VeDBA, time-activity budget, northern fur seal, Antarctic fur seal, energy expenditure, metabolic rate, foraging",
author = "Tiphaine Jeanniard-du-Dot and Christophe Guinet and Arnould, {John P. Y.} and Speakman, {John R.} and Andrew Trites",
year = "2017",
month = "2",
day = "1",
doi = "10.1111/1365-2435.12729",
language = "English",
volume = "31",
pages = "377–386",
journal = "Functional Ecology",
issn = "0269-8463",
publisher = "Blackwell Publishing Limited",
number = "2",

}

TY - JOUR

T1 - Accelerometers can measure total and activity-specific energy expenditures in free-ranging marine mammals only if linked to time-activity budgets

AU - Jeanniard-du-Dot, Tiphaine

AU - Guinet, Christophe

AU - Arnould, John P. Y.

AU - Speakman, John R.

AU - Trites, Andrew

PY - 2017/2/1

Y1 - 2017/2/1

N2 - 1-Energy expenditure is an important component of foraging ecology, but is extremely difficult to estimate in free-ranging animals and depends on how animals partition their time between different activities during foraging. Acceleration data has emerged as a new way to determine energy expenditure at a fine scale but needs to be tested and validated in wild animals. 2-This study investigated whether vectorial dynamic body acceleration (VeDBA) could accurately predict the energy expended by marine predators during a full foraging trip. We also aimed to determine whether the accuracy of predictions of energy expenditure derived from acceleration increased when partitioned by different types of at-sea activities (i.e., diving, transiting, resting and surface activities) vs calculated activity-specific metabolic rates. 3-To do so, we equipped 20 lactating northern (Callorhinus ursinus) and 20 Antarctic fur seals (Arctocephalus gazella) with GPS, time-depth recorders and tri-axial accelerometers, and obtained estimates of field metabolic rates using the doubly-labelled water (DLW) method. VeDBA was derived from tri-axial acceleration, and at-sea activities (diving, transiting, resting and surface activities) were determined using dive depth, tri-axial acceleration and traveling speed. 4-We found that VeDBA did not accurately predict the total energy expended by fur seals during their full foraging trips (R2 = 0.36). However, the accuracy of VeDBA as a predictor of total energy expenditure increased significantly when foraging trips were partitioned by activity and used activity-specific VeDBA paired with time activity budgets (R2 = 0.70). Activity-specific VeDBA also accurately predicted the energy expenditures of each activity independent of each other (R2 > 0.85). 5-Our study confirms that acceleration is a promising way to estimate energy expenditures of free-ranging marine mammals at a fine scale never attained before. However, it shows that it needs to be based on the time-activity budget that make up foraging trips rather than being derived as a single measure of VeDBA applied to entire foraging trips. Our activity-based method provides a cost-effective means to accurately calculate energy expenditures of fur seals using acceleration and time-activity budgets, a stepping stone for numerous other research fields.

AB - 1-Energy expenditure is an important component of foraging ecology, but is extremely difficult to estimate in free-ranging animals and depends on how animals partition their time between different activities during foraging. Acceleration data has emerged as a new way to determine energy expenditure at a fine scale but needs to be tested and validated in wild animals. 2-This study investigated whether vectorial dynamic body acceleration (VeDBA) could accurately predict the energy expended by marine predators during a full foraging trip. We also aimed to determine whether the accuracy of predictions of energy expenditure derived from acceleration increased when partitioned by different types of at-sea activities (i.e., diving, transiting, resting and surface activities) vs calculated activity-specific metabolic rates. 3-To do so, we equipped 20 lactating northern (Callorhinus ursinus) and 20 Antarctic fur seals (Arctocephalus gazella) with GPS, time-depth recorders and tri-axial accelerometers, and obtained estimates of field metabolic rates using the doubly-labelled water (DLW) method. VeDBA was derived from tri-axial acceleration, and at-sea activities (diving, transiting, resting and surface activities) were determined using dive depth, tri-axial acceleration and traveling speed. 4-We found that VeDBA did not accurately predict the total energy expended by fur seals during their full foraging trips (R2 = 0.36). However, the accuracy of VeDBA as a predictor of total energy expenditure increased significantly when foraging trips were partitioned by activity and used activity-specific VeDBA paired with time activity budgets (R2 = 0.70). Activity-specific VeDBA also accurately predicted the energy expenditures of each activity independent of each other (R2 > 0.85). 5-Our study confirms that acceleration is a promising way to estimate energy expenditures of free-ranging marine mammals at a fine scale never attained before. However, it shows that it needs to be based on the time-activity budget that make up foraging trips rather than being derived as a single measure of VeDBA applied to entire foraging trips. Our activity-based method provides a cost-effective means to accurately calculate energy expenditures of fur seals using acceleration and time-activity budgets, a stepping stone for numerous other research fields.

KW - acceleration

KW - VeDBA

KW - time-activity budget

KW - northern fur seal

KW - Antarctic fur seal

KW - energy expenditure

KW - metabolic rate

KW - foraging

U2 - 10.1111/1365-2435.12729

DO - 10.1111/1365-2435.12729

M3 - Article

VL - 31

SP - 377

EP - 386

JO - Functional Ecology

JF - Functional Ecology

SN - 0269-8463

IS - 2

ER -