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

Biology Open ◽  
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.

The cold shoulder: free-ranging snowshoe hares maintain a low cost of living in cold climates

2009 ◽  
Vol 87 (10) ◽  
pp. 956-964 ◽  
Author(s):  
Michael J. Sheriff ◽  
J. R. Speakman ◽  
L. Kuchel ◽  
S. Boutin ◽  
M. M. Humphries
Keyword(s):  
Metabolic Rate ◽  
High Latitude ◽  
Low Cost ◽  
Resting Metabolic Rate ◽  
Mean Field ◽  
Resource Scarcity ◽  
Doubly Labelled Water ◽  
Snowshoe Hares ◽  
Free Ranging ◽  
The Relationship

The hypothesis that cold air temperatures (Ta) constrain the metabolic diversity of high-latitude endotherms is based on the observation among birds and mammals that mean field metabolic rate (FMR) increases, whereas the variability of FMR decreases, from the warm tropics to the cold poles. However, there is a paucity of FMR measurements from above 60° latitude and below 0 °C. We measured the daily energy expenditure of a high-latitude population of free-ranging snowshoe hares ( Lepus americanus Erxleben, 1777) in Yukon, Canada, in winter (Ta-mean = –16.4 °C) and in autumn (Ta-mean = 0.5 °C). Doubly labelled water measures of FMR were approximately 20% lower in winter than in autumn, and were a similar, low multiple of resting metabolic rate in both seasons (2.04 and 1.94, respectively). The mass-corrected FMR of snowshoe hares in winter was only half the value predicted by extrapolating the relationship between FMR and Ta > 0 to –16.4 °C. These results contribute to an emerging pattern of a reversal in the relationship between FMR and Ta in free-ranging mammals from negative above 0 °C to positive below 0 °C. We refer to the positive, low Ta portion of this relationship as the cold shoulder, and suggest that it may reflect the general necessity for free-ranging mammals to use behavioural and (or) physiological means to conserve energy during long winters when cold conditions coincide with resource scarcity.

Effects of Television on Metabolic Rate: Potential Implications For Childhood Obesity

PEDIATRICS ◽  
1993 ◽  
Vol 91 (2) ◽  
pp. 281-286
Author(s):  
Robert C. Klesges ◽  
Mary L. Shelton ◽  
Lisa M. Klesges
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Television Viewing ◽  
Resting Energy Expenditure ◽  
Normal Weight ◽  
Laboratory Setting ◽  
Obese Children ◽  
Two Measures ◽  
The Relationship ◽  
Resting Energy

The effects of television viewing on resting energy expenditure (metabolic rate) in obese and normal-weight children were studied in a laboratory setting. Subjects were 15 obese children and 16 normal-weight children whose ages ranged from 8 to 12 years. All subjects had two measures of resting energy expenditure obtained while at rest and one measurement of energy expenditure taken while viewing television. Results indicated that metabolic rate during television viewing was significantly lower (mean decrease of 211 kcal extrapolated to a day) than during rest. Obese children tended to have a larger decrease, although this difference was not statistically significant (262 kcal/d vs 167 kcal/d, respectively). It was concluded that television viewing has a fairly profound lowering effect of metabolic rate and may be a mechanism for the relationship between obesity and amount of television viewing.

The energy expenditure of free-ranging black-browed albatross

1995 ◽  
Vol 350 (1332) ◽  
pp. 119-131 ◽  
Keyword(s):  
Energy Expenditure ◽  
Salt Water ◽  
Doubly Labelled Water ◽  
Data Loggers ◽  
Satellite Transmitters ◽  
The Mean ◽  
High Level ◽  
Free Ranging ◽  
Combining Information ◽  
Previous Assumption

As heart rate ( f H ) can be used to determine the energy expenditure of black-browed albatrosses ( Diomedea melanophrys ) (Bevan et al. 1994), data loggers - recording f H and abdominal temperature ( T ab ) -were implanted into free-ranging black-browed albatrosses breeding at South Georgia. Five birds also had salt water switches (sws) attached to one leg to record when the birds were on the water, and two others had satellite transmitters attached to their back to determine the birds’ position at sea. The birds were released into their natural environment and recaptured, on average, 23 days later when the data loggers were removed. The f H data were then converted into estimates of energy expenditure (ee) using a previously derived equation. The mean EE during incubation and brooding were 2.22 and 2.42 W kg -1 , respectively. When the birds were foraging at sea, EE increased to between 4.63 and 5.80 W kg -1 , depending on the phase of the reproductive cycle. As the birds spent approximately the same length of time at the nest and at sea during incubation and brooding, the overall mean ee during these phases were 3.63 and 3.54 W kg -1 respectively. These rates are significantly lower than that during the chick-rearing phase when a high level of foraging EE is maintained almost continuously. By combining information from the sws with the f H data, it was possible to determine the EE of the birds when on the water (5.77 W kg -1 ) and when flying (6.21 W kg -1 ). These values are approximately twice the estimated basal metabolic rate (BMR) for the species. The energy costs of flight are half previous values, estimated using the doubly labelled water technique, because of the previous assumption that birds on the water have an EE equivalent to BMR. When the birds were on the nest, T ab was 39.3 + 0.4 °C and this changed very little with time. However, when they were at sea, T ab showed large variations, depending on the behaviour of the bird. Information from the sws indicated that all large drops (> 0.5 °C) in Tab occurred when the birds were on water. The mean minimum value reached was 32.5 + 2.0 °C. It is likely that ingestion of prey or water are the major causes of this decrease. This is the first study to have used f H extensively to determine the EE of a free-ranging marine bird. The advantages of using this technique are that data can be obtained over long durations with high resolution, permitting the EE of different activities to be estimated.

scholarly journals Quantifying the free living energy exchanges of Arctic ungulates with stable isotopes

Rangifer ◽  
2000 ◽  
Vol 20 (2-3) ◽  
pp. 59 ◽  
Author(s):  
Paul Haggarty
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Energy Requirement ◽  
Ecological Impact ◽  
The Arctic ◽  
Unknown Parameters ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Energy Exchanges ◽  
Free Ranging

When natural diets meet an animal's requirement for energy, other essential nutrients will usually be supplied in amounts at least sufficient for survival. Knowledge of the energy requirements of free ranging species under typical conditions are important in assessing both their nutritional needs and their ecological impact. The doubly labelled water (DLW) method is currently the most promising objective field methodology for estimating free living energy expenditure but expenditure is only equal to the energy requirement when an animal is in energy balance. Reproduction and seasonal cycles of fat deposition and utilization represent significant components of the energy budget of arctic ungulates but the information gained in the course of a typical DLW study may be used to estimate processes such as milk output and fat storage and mobilization in order to predict requirements from expenditure. The DLW method has been exhaustively validated under highly controlled conditions and the introduction of innovations such as faecal sampling for the estimation of body water isotopic enrichment, the availability of appropriate correction factors and stoichiometrics for known sources of error, and iterative calculation of unknown parameters, have produced a methodology suitable for use in truly free ranging species. The few studies carried out so far in arctic ungulates indicate that previous predictions have generally underestimated the true level of expenditure, that there is considerable between animal variation in the level of expenditure and that this is largely determined by physical activity. The disadvantages of the DLW methodology are that it remains expensive and the isotope analysis is technically demanding. Furthermore, although DLW can provide an accurate value for free living energy expenditure, it is often important to have information on the individual components of expenditure, for example the relative contribution of physical activity and thermoregulatory thermogenesis, in order to interpret the values for overall expenditure. For these reasons the most valuable use of the DLW method in the field may be to validate factorial models and other approaches so that they may be used with confidence. Additional important information on the energy exchanges of free ranging animals may be obtained from other stable isotope methodologies. In addition to the use of the isotopes 2H and lsO in the DLW method, natural variations in the abundance of "C and 15N in the arctic environment may be exploited to study diet selection in truly free living arctic ungulates.

scholarly journals Figs Are More Than Fallback Foods: The Relationship betweenFicusandCebusin a Tropical Dry Forest

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Nigel A. Parr ◽  
Amanda D. Melin ◽  
Linda Marie Fedigan
Keyword(s):  
Energy Intake ◽  
Tropical Dry Forest ◽  
Travel Speed ◽  
Dry Forest ◽  
Energy Output ◽  
Fallback Foods ◽  
Behavioural Patterns ◽  
Energy Maximization ◽  
Fig Trees ◽  
The Relationship

In many studies on primate feeding ecology, figs (Ficusspp.) are characterized as fallback foods, utilized only when preferred sources of food are unavailable. However, for white-faced capuchin monkeys (Cebus capucinus) living in northwestern Costa Rica, figs are a consistently important resource and may increase groupwide energy intake. We investigated whether visits to figs affect ranging and behavioural patterns of capuchins. Although daily range length and average travel speed do not differ on days when fig trees are visited, capuchins spend more time in directed travel and more time stationary on “fig days”. Capuchins also increase time spent foraging for fruit and decrease time spent foraging for invertebrates on days when figs trees are visited. Capuchins experience higher energy intake and lower energy output on “fig” days. Thus, the patterns of foraging for figs support an energy-maximization strategy and constitute an important nutritional resource for capuchins.

scholarly journals The Psychobiology of Hunger – A Scientific Perspective

Topoi ◽  
2020 ◽  
Author(s):  
Kristine Beaulieu ◽  
John Blundell
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Environmental Influence ◽  
Empirical Studies ◽  
Resting Metabolic Rate ◽  
Conscious State ◽  
Cultural Factors ◽  
Biological Processes ◽  
Gastrointestinal Peptides ◽  
The Relationship

Abstract From a scientific perspective, hunger can be regarded as an identifiable conscious sensation which can be distinguished from other conscious states (e.g., pain, fear). The hunger state can be measured and is a marker of the existence of underlying biological processes. Measured hunger is functional and is normally associated with the act of eating. However, the conscious state of hunger, although driven physiologically, is not exclusively determined by biology; there is an environmental influence that can modulate its intensity and periodicity, and cultural factors that shape the appropriateness of the expression of hunger. Within a psychobiological framework, hunger can be considered as the expression of a ‘need state’ which mediates between biological requirements and environmental (nutritional) satisfaction. Our empirical studies show that hunger is clearly associated with biological signals (e.g., resting metabolic rate and some gastrointestinal peptides) and is central to the relationship between energy expenditure and energy intake.

Correlates of seasonal changes in metabolism in Atlantic harbour seals (Phoca vitulina concolor)

1998 ◽  
Vol 76 (8) ◽  
pp. 1520-1528 ◽  
Author(s):  
D A Rosen ◽  
D Renouf
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Total Energy ◽  
Energy Intake ◽  
Body Mass ◽  
Seasonal Changes ◽  
Energy Use ◽  
Phoca Vitulina ◽  
Harbour Seals ◽  
Gross Energy

This study tested the hypothesis that seasonal variation in resting metabolic rate (RMR) was more closely related to changes in total energy use than to energy intake. It also quantified the extent to which variation in metabolism contributed to changes in total energy expenditure. RMR, gross energy intake, and body mass and composition were measured in six captive Atlantic harbour seals (Phoca vitulina concolor) over 16 months. Gross energy intake during the year (across all seals) averaged 25.4 ± 4.1 MJ/d (mean ± SD). The energy used by the seals Eused a composite measure of energy expenditure from ingested energy and tissue catabolism) averaged 19.2 ± 3.4 MJ/d. RMR averaged 11.2 ± 1.5 MJ/d during the year, while mass-corrected metabolism declined with age. The seals displayed significant changes in both absolute and mass-corrected metabolism during the year. Overall, Eused was a stronger predictor of changes in metabolism than either gross energy intake or body mass. Mass-corrected metabolic rate was more closely related to Eused than was absolute metabolism. Energy changes in metabolism during the year (range = 6.9 ± 1.9 MJ/d) were minor compared with those in Eused (27.8 ± 7.3 MJ/d). These results suggest that seasonal changes in metabolism were a response to, or facilitated by, concurrent changes in Eused but were not the cause of variation in Eused. Rather, variation in both RMR and Eused was the result of changes in other bioenergetic components of the seals' energy budget, such as activity.

Field Metabolic-Rate and Food Requirement of a Small Dasyurid Marsupial, Sminthopsis-Crassicaudata

1988 ◽  
Vol 36 (3) ◽  
pp. 293 ◽  
Author(s):  
KA Nagy ◽  
AK Lee ◽  
RW Martin ◽  
MR Fleming
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Water Flux ◽  
Metabolic Rates ◽  
Feeding Rates ◽  
Doubly Labelled Water ◽  
Sminthopsis Crassicaudata ◽  
Food Requirement ◽  
Field Metabolic Rates ◽  
Free Ranging

Field metabolic rates (FMRs) and rates of water flux in free-ranging fat-tailed dunnarts, Sminthopsis crassicaudata, were measured during spring (late October) using doubly labelled water. Feeding rates were estimated on the basis of water and energy fluxes. FMRs averaged 68.7 kJ d-' in adults (mean body mass= 16.6 g), and were 29.2 kJ d-' in juveniles (6.1 g). These FMRs are 6.6 times basal metabolic rate (BMR), and are much higher than the hypothetical maxima of four to five times BMR. Other dasyurid marsupials also have high FMR/BMR ratios, but so does a small petaurid marsupial. S. crassicaudata consumed 80-90% of its body mass in arthropods each day. The diet of arthropods apparently provided enough water for the animals to maintain water balance without drinking during this study.

Seasonal daily, daytime and night-time field metabolic rates in Arabian babblers (Turdoides squamiceps)

2002 ◽  
Vol 205 (22) ◽  
pp. 3571-3575 ◽  
Author(s):  
Avner Anava ◽  
Michael Kam ◽  
Amiram Shkolnik ◽  
A. Allan Degen
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Breeding Season ◽  
Seasonal Patterns ◽  
Metabolic Rates ◽  
Night Time ◽  
Doubly Labelled Water ◽  
Influx Rate ◽  
Water Influx ◽  
Field Metabolic Rates

SUMMARY Arabian babblers (Turdoides squamiceps; mean adult body mass=72.5 g) inhabit extreme deserts of Israel. Previous studies have shown that their daily field metabolic rates are similar in winter and summer and that there is an increase during the breeding season. We hypothesized that the difference in seasonal daily field metabolic rate would be a consequence of differences in daytime metabolic rate, and that night-time metabolic rate would be similar during the three seasons. We used doubly labelled water to determine daily,daytime and night-time field metabolic and water-influx rates in breeding babblers in spring and nonbreeding babblers in winter and summer. Daily and daytime energy expenditure rates were higher during the breeding season than during either summer or winter, but there was no difference among seasons in night-time energy expenditure rates. Thus, our hypothesis was supported. The daytime field metabolic rates in summer and winter nonbreeding babblers were 3.92× and 4.32× the resting metabolic rate (RMR),respectively, and in breeding babblers was 5.04× RMR, whereas the night-time field metabolic rates ranged between 1.26× RMR and 1.35× RMR in the three seasons. Daily and daytime water-influx rates were highest in winter, intermediate during the breeding season and lowest in summer, but there was no difference among seasons in night-time water-influx rate. Daytime water-influx rate was greater than night-time water-influx rate by 2.5-fold in summer, 3.9-fold in the breeding season and 6.75-fold in winter. Seasonal patterns of daily and daytime energy expenditure were similar, as were seasonal patterns of daily and daytime water influx. Daily and daytime energy expenditure and water-influx rates differed among seasons whereas night-time rates of both did not. Daily and daytime field metabolic rates of babblers were highest during the breeding season, whereas daily and daytime water-influx rates were highest in winter.

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