INVESTIGADORES
QUINTANA Flavio Roberto
artículos
Título:
Moving towards acceleration for estimates of activity-specific metabolic rate in free-living animals: the case of the cormorant
Autor/es:
WILSON, R.P.; WHITE, C.R,; QUINTANA, F.; LEWIS, G. H.; LIEBSCH, N.; MARTIN, G. R.; BUTLER, P.
Revista:
JOURNAL OF ANIMAL ECOLOGY
Editorial:
Blackwell Publishing
Referencias:
Lugar: Singapore; Año: 2006 vol. 75 p. 1081 - 1090
ISSN:
0021-8790
Resumen:
Time and energy are key currencies in
animal ecology, and judicious management of these is a primary focus for
natural selection. At present, however, there are only two main methods
for estimation of rate of energy expenditure in the field, both of which
have been used with success but both also have limitations.
The deployment of loggers that measure
acceleration is emerging as a powerful tool for quantifying the behaviour
of free-living animals. Given that animal movement requires the use of
energy, the accelerometry technique potentially has application in the
quantification of rate of energy expenditure.
In the present study, we test the
hypothesis that acceleration can serve as a proxy for rate of energy
expenditure in free-living animals. We measured rate of energy expenditure
as rates of O2 consumption (V˙ O2) and CO2 production (V˙ CO2) in Great Cormorants (Phalacrocorax carbo) at rest and
during pedestrian exercise. V˙ O2 and
V˙ CO2 were then related to overall dynamic body
acceleration (ODBA) measured with an externally- attached three-axis
accelerometer.
To verify that the approach identifies
expected trends in V˙ O2 from situations with variable power
requirements, we measured ODBA in free-living Imperial Cormorants (Phalacrocorax atriceps) during
foraging trips. We compared ODBA during return and outward foraging
flights, when birds are expected to be laden and not laden with captured
fish, respectively. We also examined changes in ODBA during the descent
phase of diving, when power requirements are predicted to decrease with
depth due to changes in buoyancy associated with compression of plumage
and respiratory air.
Both V˙ O2 and
V˙ CO2 were significantly positively associated
with ODBA in Great Cormorants. This suggests that accelerometric
measurements of ODBA can be used to estimate V˙ O2 and
V˙ CO2, and, with some additional assumptions
regarding metabolic substrate use and the energy equivalence of O2 and CO2, that ODBA can be used
to estimate the activity specific rate of energy expenditure of
free-living cormorants.
In free-living Imperial Cormorants, ODBA,
and hence estimated V˙ O2, was higher during the return flight of a
foraging bout, and decreased with depth during the descent phase of a
dive, supporting the use of accelerometry for the determination of
activity-specific rate of energy expenditure.