High Rates of Energy Expenditure and Water Flux in Free‐Ranging Point Reyes Mountain BeaversAplodontia rufa phaea

Water flux and daily energy expenditure were measured with doubly labeled water (3HH18O) in two insectivorous sympatric species of Lacertidae of Kerkennah islands (Tunisia), Eremias olivieri (mean body mass: 1.1 g) and Acanthodactylus pardalis (4.5 g) in a semiarid environment. Water turnover and field metabolic rate of Eremias olivieri (174 μL H2O g−1 d−1 and 250 J g−1 d−1) were, respectively, 2.5 and 5 times higher than those of Acanthodactylus pardalis (70 μL H2O g−1 d−1 and 52 J g−1 d−1). The water turnover of Eremias olivieri is one of the highest known among insectivorous lizards, and the daily energy expenditure of Acanthodactylus pardalis one of the lowest. The most plausible explanations are the differences in the size of the prey eaten by each species at this time of the season and in the duration of daily activity; the daily activity of Acanthodactylus pardalis is short (4.5 h d−1) although it is a sit-and-wait predator, whereas Eremias olivieri is active regularly every day for a longer period (7.5 h d−1) although it is an active forager. The high values of water turnover in Eremias olivieri suggest that food is not the only source of water for lizards in this particular insular environment.

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Energy Expenditure and Water Flux of Rüppell’s Foxes in Saudi Arabia

Physiological and Biochemical Zoology ◽

10.1086/344490 ◽

2002 ◽

Vol 75 (5) ◽

pp. 479-488 ◽

Cited By ~ 17

Author(s):

Joseph B. Williams ◽

Danny Lenain ◽

Stephane Ostrowski ◽

B. I. Tieleman ◽

Philip J. Seddon

Keyword(s):

Saudi Arabia ◽

Energy Expenditure ◽

Water Flux

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Estimation of energy needs in the free-ranging goat with particular reference to the assessment of its energy expenditure by the 13C-bicarbonate method

Small Ruminant Research ◽

10.1016/s0921-4488(03)00146-9 ◽

2003 ◽

Vol 49 (3) ◽

pp. 303-318 ◽

Cited By ~ 41

Author(s):

M. Lachica ◽

J.F. Aguilera

Keyword(s):

Energy Expenditure ◽

Energy Needs ◽

Free Ranging

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Validating accelerometry-derived proxies of energy expenditure using the doubly-labelled water method in the smallest penguin species

Biology Open ◽

10.1242/bio.055475 ◽

2021 ◽

pp. bio.055475

Author(s):

G. J. Sutton ◽

J. A. Botha ◽

J. R. Speakman ◽

J. P. Y. Arnould

Keyword(s):

Energy Expenditure ◽

Metabolic Rate ◽

Energy Use ◽

Travel Speed ◽

Specific Energy Expenditure ◽

Doubly Labelled Water ◽

Data Collection And Analysis ◽

Behavioural Patterns ◽

Free Ranging ◽

The Relationship

Understanding energy use is central to understanding an animal's physiological and behavioural ecology. However, directly measuring energy expenditure in free-ranging animals is inherently difficult. The doubly-labelled water (DLW) method is widely used to investigate energy expenditure in a range of taxa. Although reliable, DLW data collection and analysis is both financially costly and time consuming. Dynamic body acceleration (e.g. VeDBA) calculated from animal-borne accelerometers has been used to determine behavioural patterns, and is increasingly being used as a proxy for energy expenditure. Still its performance as a proxy for energy expenditure in free-ranging animals is not well established and requires validation against established methods. In the present study, the relationship between VeDBA and the at-sea metabolic rate calculated from DLW was investigated in little penguins (Eudyptula minor) using three approaches. Both in a simple correlation and activity-specific approaches were shown to be good predictors of at-sea metabolic rate. The third approach using activity-specific energy expenditure values obtained from literature did not accurately calculate the energy expended by individuals. However, all three approaches were significantly strengthened by the addition of mean horizontal travel speed. These results provide validation for the use of accelerometry as a proxy for energy expenditure and show how energy expenditure may be influenced by both individual behaviour and environmental conditions.

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Energy expenditure of free-living reindeer estimated by the doubly labelled water method

Rangifer ◽

10.7557/2.20.4.1516 ◽

2000 ◽

Vol 20 (2-3) ◽

pp. 211 ◽

Cited By ~ 10

Author(s):

Geir Gotaas ◽

Eric Milne ◽

Paul Haggarty ◽

Nicholas J.C. Tyler

Keyword(s):

Energy Expenditure ◽

Rangifer Tarandus ◽

Water Flux ◽

Co2 Production ◽

Wild Ungulates ◽

Free Living ◽

Doubly Labelled Water ◽

Svalbard Reindeer ◽

Mountain Pasture ◽

The Mean

The doubly labelled water (DLW) method was used to measure total energy expenditure (TEE) in three male reindeer (Rangifer tarandus tarandus) aged 22 months in winter (February) while the animals were living unrestricted at natural mountain pasture in northern Norway (69°20'N). The concentrations of 2H and l8O were measured in water extracted from samples of faeces collecred from the animals 0.4 and 11.2 days after injection of the isotopes. Calculated rates of water flux and CO2-production were adjusted to compensate for estimated losses of 2H in faecal solids and in methane produced by microbial fermentation of forage in the rumen. The mean specific TEE in the three animals was 3.057 W.kg-1 (range 2.436 - 3.728 W.kg1). This value is 64% higher than TEE measured by the DLW method in four captive, non-pregnant adult female reindeer in winter and probably mainly reflects higher levels of locomotor activity in the free-living animals. Previous estimates of TEE in free-living Rangifer in winter based on factorial models range from 3.038 W.kg-1 in female woodland caribou (R. t. caribou) to 1.813 W.kg-1 in female Svalbard reindeer (R. t. platyrhynchus). Thus, it seems that existing factorial models are unlikely to overestimate TEE in reindeer/caribou: they may, instead, be unduly conservative. While the present study serves as a general validation of the factorial approach, we suggest that the route to progress in the understanding of field energetics in wild ungulates is via application of the DLW method.

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Determining energy expenditure in preterm infants: comparison of 2H(2)18O method and indirect calorimetry

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1992.263.3.r685 ◽

1992 ◽

Vol 263 (3) ◽

pp. R685-R692 ◽

Cited By ~ 1

Author(s):

C. L. Jensen ◽

N. F. Butte ◽

W. W. Wong ◽

J. K. Moon

Keyword(s):

Heart Rate ◽

Energy Expenditure ◽

Preterm Infants ◽

Indirect Calorimetry ◽

Water Flux ◽

High Ratio ◽

Individual Variability ◽

Study Time ◽

Co2 Production ◽

Turnover Rates

The doubly labeled water (2H(2)18O) method used to estimate total energy expenditure (EETotal) is particularly sensitive to analytic error in preterm infants, because of their high percentage of body water and the high ratio of water flux to CO2 production. To evaluate further use of this method, the EE of 12 preterm infants was measured by indirect calorimetry and 2H(2)18O simultaneously and continuously for 5 days. Initial infant weight, age, and postconceptional age were (means +/- SD) 1,674 +/- 173 g, 4.4 +/- 2.6 wk, and 34.6 +/- 1.6 wk, respectively. The indirect calorimeter system included an air-temperature-controlled chamber and heart rate monitor. EE was measured by indirect calorimetry for 85.6 +/- 4.7% of study time and estimated from the linear regression of heart rate on EE for 14.4 +/- 4.7% of study time. The 2H(2)18O method entailed an initial dose of 100 mg 2H2O and 250 mg 18O/kg and a final dose of 75 mg 18O/kg; urine was collected twice daily. 2H and 18O enrichments were measured by gas-isotope-ratio mass spectrometry. EE was calculated from measured 2H and 18O dilution spaces (NH, NO), turnover rates (kH, kO), and measured respiratory quotient. The ratio of 2H to 18O dilution spaces was 1.01 +/- 0.01 and the ratio of kO to kH was 1.16 +/- 0.04. Estimation of EE from 2H(2)18O and indirect calorimetry agreed within 1%, although individual variability in methods was large.

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Energy Expenditure of Free-Ranging Chicks of the Cape GannetMorus capensis

Physiological and Biochemical Zoology ◽

10.1086/681671 ◽

2015 ◽

Vol 88 (4) ◽

pp. 406-415 ◽

Cited By ~ 3

Author(s):

René A. Navarro ◽

Ralf H. E. Mullers ◽

Haro A. J. Meijer ◽

Les G. Underhill

Keyword(s):

Energy Expenditure ◽

Free Ranging

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Field Metabolism and Food Consumption of Savannah Sparrows during the Breeding Season

The Auk ◽

10.1093/auk/104.2.277 ◽

1987 ◽

Vol 104 (2) ◽

pp. 277-289 ◽

Cited By ~ 44

Author(s):

Joseph B. Williams

Keyword(s):

Energy Expenditure ◽

Brood Size ◽

Water Flux ◽

Water Losses ◽

Time Activity ◽

Passerculus Sandwichensis ◽

Nestling Period ◽

Relationship Construction ◽

The Relationship ◽

Savannah Sparrows

Abstract I applied the doubly labeled water (DLW) technique to measure rates of water flux and energy expenditure of Savannah Sparrows (Passerculus sandwichensis) during two breeding seasons on Kent Island, New Brunswick, Canada. Simultaneous to DLW measurements, I constructed time-activity budgets for territorial males, monitored nest attentiveness for incubating females, and quantified frequency of nest visitation for parents feeding young. To ascertain the relationship between brood size and adult energy expenditure, I measured the energy expenditure of adults feeding 2, 4, and 6 nestlings. There was little difference in field metabolic rates (FMR) between territorial males [161.0\pm 21.7 (SD) ml CO2/h). and males that fed 4 nestlings (157.6 ± 19.7 ml CO2/h). Incubating females expired CO2 at rates lower than males during the same time period (134.4 ± 7.9 vs. $161.0 ± 21.7 ml CO2/h but similar to rates for females feeding 4 young, the normal brood size ($134.4 ± 7.9 ml CO2/h for incubating females vs. $136.5 ± 26.9 ml CO2h for females feeding young). Incubating females expended energy at a lower rate than females making 8 or more trips to the nest per hour, the average feeding rate for females late in the nestling period. For males and females together, water influx and efflux rates averaged 17.1 ± 3.2 and 17.2 ± 3.0 ml H20/day, suggesting that birds balanced water intake against water losses. Mean daily solar radiation (MDSR; W/ m2) also influenced FMR during the nestling period. The equation ml CO2/h=172.6-0.07 (MDSR) described the relationship. When brood sizes were manipulated, parents responded by altering their frequency of nest visitation; as frequency increased, so did the FMR of females but not of males. The equation ml CO2/h =98.4 + 5.3 (mean visits/h) described the relationship. Construction of a food budget indicated that, on average, territorial males consumed 21.1 g fresh arthropods per day, while incubating females ingested 17.5 g/day or 210.0 g during the 12-day incubation period. Through the 8-day nestling period, males augmented their foraging by 75%, females by 87%, to feed a brood of 4.

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