Validating the relationship between 3-dimensional body acceleration and oxygen consumption in trained Steller sea lions

Abstract

We tested the ability of overall dynamic body acceleration (ODBA) to predict the rate of oxygen consumption ([Formula: see text]) in freely diving Steller sea lions (Eumetopias jubatus) while resting at the surface and diving. The trained sea lions executed three dive types-single dives, bouts of multiple long dives with 4-6 dives per bout, or bouts of multiple short dives with 10-12 dives per bout-to depths of 40 m, resulting in a range of activity and oxygen consumption levels. Average metabolic rate (AMR) over the dive cycle or dive bout calculated was calculated from [Formula: see text]. We found that ODBA could statistically predict AMR when data from all dive types were combined, but that dive type was a significant model factor. However, there were no significant linear relationships between AMR and ODBA when data for each dive type were analyzed separately. The potential relationships between AMR and ODBA were not improved by including dive duration, food consumed, proportion of dive cycle spent submerged, or number of dives per bout. It is not clear whether the lack of predictive power within dive type was due to low statistical power, or whether it reflected a true absence of a relationship between ODBA and AMR. The average percent error for predicting AMR from ODBA was 7-11 %, and standard error of the estimated AMR was 5-32 %. Overall, the extensive range of dive behaviors and physiological conditions we tested indicated that ODBA was not suitable for estimating AMR in the field due to considerable error and the inconclusive effects of dive type.

Counting calories in cormorants: dynamic body acceleration predicts daily energy expenditure measured in pelagic cormorants

“…In other diving homeotherms, activity does not correlate well with energy expenditure (Fahlman et al, 2008;Halsey et al, 2011;Meir et al, 2013;Volpov et al, 2015). We argue that in addition to mechanical activity, dive costs are strongly affected by the suppression of oxygen consumption via reduced heart rate, body temperature, shunting of blood past non-vital organs and other mechanisms, and that physiology, in addition to physics, plays an important role in oxygen consumption during dives.…”

“…Those issues explain why the relationship between DBA and metabolism is different between flying and walking (Laich et al, 2011;Elliott et al, 2013a). Indeed, several studies have failed to find a relationship between DBA and energy expenditure, either when body mass variation may have confounded relationships (Guillemette and Butler, 2012;Dalton et al, 2014;Volpov et al, 2015; M. Kristiansen, Can energy expenditure of free-ranging kittiwakes be estimated by body acceleration? MSc thesis, University of Tromso, 2014) or when cardiovascular adjustments during diving overwhelmed any relationship with mechanical work (Halsey et al, 2011;Meir et al, 2013).…”

Key Questions in Marine Megafauna Movement Ecology

“…Energy expenditure derived from accelerometer data shows great promise for estimating the metabolic rate of free-living animals by providing a robust measure of activity (e.g. [84] but see [85]) allowing various models of optimal movement to be tested [7].…”

Processing of acceleration and dive data on‐board satellite relay tags to investigate diving and foraging behaviour in free‐ranging marine predators

“…For example, prey catch attempt (PrCA) behaviours can be identified from peaks in acceleration indicative of rapid head movements (Gallon et al., ; Naito, Bornemann, Takahashi, McIntyre, & Plotz, ; Suzuki, Naito, Folkow, Miyazaki, & Blix, ; Viviant et al., ; Volpov, Hoskins, et al., ), whilst proxies of energetic expenditure (e.g. swimming effort) can be calculated by isolating dynamic movement rates (Jeanniard‐du‐Dot, Guinet, Arnould, Speakman, & Trites, ; Sato, Mitani, Cameron, Siniff, & Naito, ; Volpov, Rosen, Trites, & Arnould, ). The latter of these can additionally be used in tandem with estimations of pitch and vertical speed to give a relative measure of body condition (Aoki et al., ; Richard et al., ).…”