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.

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 Relationship of Mode and Intensity of Training on Resting Metabolic Rate in Women

2001 ◽  
Vol 11 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Heidi K. Byrne ◽  
Jack H. Wilmore
Keyword(s):  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Women Subjects ◽  
Present Cross Sectional Study ◽  
Significant Difference ◽  
Level Of Training ◽  
The Relationship ◽  
Aerobically Trained

The present cross-sectional study was designed to investigate the relationship between exercise training and resting metabolic rate (RMR). The focus of this investigation was to compare RMR in aerobically trained (AT), resistance trained (RT), and untrained (UNT) women. Subjects were also classified as highly trained (HT), moderately trained (MT), or untrained (UNT) in order to examine the relationship between RMR and level of training. Sixty-one women between the ages of 18 and 46 years volunteered to serve as subjects in this study. Each subject completed measurements of body composition, maximal oxygen uptake (V̇O2max), and two consecutive measurements of RMR. The data presented show that there was no significant difference in resting metabolic rate between resistance-trained, aerobically trained, and control subjects. However, when grouped by intensity of training, there was a trend for an increased resting metabolic rate (kcal/day) in the highly trained subjects, regardless of mode of training.

Field Metabolic Rate and Water Flux of Nectarivorous Honeyeaters

1996 ◽  
Vol 44 (5) ◽  
pp. 445 ◽  
Author(s):  
WW Weathers ◽  
DC Paton ◽  
RS Seymour
Keyword(s):  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Low Cost ◽  
Water Flux ◽  
Doubly Labelled Water ◽  
Field Metabolic Rate ◽  
Influx Rate ◽  
Water Influx ◽  
Average Water ◽  
Foraging Tactic

Field metabolic rate (FMR) and water influx of New Holland honeyeaters (Phylidonyris novaehollandiae), eastern spinebills (Acanthorhynchus tenuirostris) and a crescent honeyeater (P. pyrrhoptera) were measured by the doubly labelled water technique. New Holland honeyeaters had just finished breeding and were beginning their summer moult. They ranged in mass from 15.4 to 21.0 g (mean = 17.3 g, n = 12) and had FMRs averaging 8.8 mt CO2 g(-1) h(-1) or 77.6 kJ day(-1), which was 2.8 times their measured basal metabolic rate (BMR). Their water influx rate averaged 10.7 mL day(-1). Eastern spinebills were still feeding young and had yet to begin moulting. They ranged in mass from 8.0 to 10.7 g (mean = 9.7 g, n = 6), had FMRs averaging 10.9 mL CO2 g(-1) h(-1) or 52.9 kJ day(-1) (2.5 times their measured BMR), and had an average water influx rate of 8.7 mL day(-1). FMR and water influx of a single 14.6-g crescent honeyeater, which was in late primary moult, were 75.9 kJ day(-1) (2.7 times measured BMR) and 12.5 mL day(-1). The FMR of New Holland honeyeaters varied inversely with mean standard operative temperature (T-es) calculated for values of T-es below 20 degrees C as follows: FMR (kJ day(-1)) = 134 - 5.47 T-es (n = 12, r(2) = 0.52). Honeyeater FMRs were much lower than would be predicted allometrically for hummingbirds of the same mass, reflecting the honeyeaters' low-cost foraging tactic of consuming nectar while perched.

scholarly journals Association Between Cardiac High-Energy Phosphate Metabolism and Whole Body Metabolism in Healthy Female Adults

2021 ◽  
pp. 393-399
Author(s):  
P WIBOWO ◽  
S CHARMAN ◽  
N OKWOSE ◽  
L VELICKI ◽  
D POPOVIC ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
High Energy ◽  
Whole Body ◽  
Phosphate Metabolism ◽  
High Energy Phosphate ◽  
Glucose Levels ◽  
Whole Body Metabolism ◽  
High Energy Phosphate Metabolism ◽  
The Relationship

Decline in cardiac high-energy phosphate metabolism [phosphocreatine-to-ATP (PCr/ATP) ratio] and whole body metabolism increase the risk of heart failure and metabolic diseases. The aim of the present study was to assess the relationship between PCr/ATP ratio and measures of body metabolic function. A total of 35 healthy women (56±14.0 years of age) underwent cardiac 31P magnetic resonance spectroscopy to assess PCr/ATP ratio – an index of cardiac high-energy phosphate metabolism. Fasting and 2-hour glucose levels were assessed using oral glucose tolerance test. Indirect calorimetry was performed to determine oxygen consumption and resting metabolic rate. There were no significant relationships between PCr/ATP ratio and resting metabolic rate (r=-0.09, p=0.62), oxygen consumption (r=-0.11, p=0.54), fasting glucose levels (r=-0.31, p=0.07), and 2-hour plasma glucose (r=-0.10, p=0.58). Adjusted analysis for covariates including age, body mass index, fat mass, and physical activity, had no significant influence on the relationship between PCr/ATP ratio and body metabolism. In conclusion, the lack of relationship between cardiac PCr/ATP ratio, glucose control and metabolic rate may suggest that overall metabolic function does not influence cardiac high-energy phosphate metabolism.

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.

Vitamin D Status and Resting Metabolic Rate May Modify through Expression of Vitamin D Receptor and Peroxisome Proliferator-Activated Receptor Gamma Coactivator-1 Alpha Gene in Overweight and Obese Adults

2017 ◽  
Vol 72 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Seyedeh Forough Sajjadi ◽  
Khadijeh Mirzaei ◽  
Leila Khorrami-Nezhad ◽  
Zhila Maghbooli ◽  
Seyed Ali Keshavarz
Keyword(s):  
Vitamin D ◽  
Body Weight ◽  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Fat Free Mass ◽  
Peroxisome Proliferator ◽  
Vitamin D Status ◽  
Obese Adults ◽  
Peroxisome Proliferator Activated Receptor ◽  
The Relationship

Background: Resting metabolic rate (RMR) used to prognosticate and measure the amount of energy required. Vitamin D is known as a new predictor of RMR. The aim of this study is to investigate the relationship between vitamin D effects on RMR in connection with the vitamin D receptor (VDR) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) gene expression. Methods: We enrolled 298 overweight and obese adults in this cross-sectional study. Body mass index (BMI), fat mass, fat-free mass, insulin level, visceral fat, and vitamin D status were assessed. RMR was measured by means of indirect calorimetry. The real-time polymerase chain reaction using specific primer pairs for VDR and PGC-1α was performed. Results: There were significant differences in terms of fat free mass, fat percentage, insulin levels, RMR/kg body weight, and RMR/BMI, VDR, and PGC-1α among participants were categorized based on the vitamin D status. But after using general linear model for adjusting, all significant results missed their effectiveness except RMR/kg body weight and VDR. Linear regression analysis used to show the mediatory role of VDR and PGC-1α on the RMR/kg body weight and vitamin D status relationship. Our results showed that VDR had a mediatory effect on the relationship between RMR/kg body weight and vitamin D status (β = 0.38, 95% CI –0.48 to 1.60; β = –1.24, 95% CI –5.36 to 1.70). However, PGC-1α did not affect the relationship between RMR/kg body weight and vitamin D status (β = 0.50, 95% CI = –0.02 to 3.42; β = 0.59, 95% CI 0.14–3.90). Conclusion: Our study showed the mediatory effect of VDR gene expression in the association of 25(OH)2D plasma levels and resting metabolic rate among obese individuals.

scholarly journals Resting metabolic rate and morphology in mice (Mus musculus) selected for high and low food intake

2001 ◽  
Vol 204 (4) ◽  
pp. 777-784 ◽  
Author(s):  
C. Selman ◽  
S. Lumsden ◽  
L. Bunger ◽  
W.G. Hill ◽  
J.R. Speakman
Keyword(s):  
Regression Analysis ◽  
Food Intake ◽  
Metabolic Rate ◽  
Body Mass ◽  
Resting Metabolic Rate ◽  
Strain Differences ◽  
Dry Mass ◽  
Intestine Length ◽  
Body Components ◽  
The Relationship

We investigated the relationship between resting metabolic rate (RMR) and various morphological parameters in non-breeding mice, selected for high and low food intake corrected for body mass. RMR was measured at 30 degrees C, and mice were subsequently killed and dissected into 19 body components. High-food-intake mice had significantly greater body masses and a significantly elevated RMR compared with the low-intake mice. Data pooled across strains indicated that body mass, sex and strain together explained over 56 % of the observed variation in RMR. The effects of strain and sex on RMR and tissue morphology were removed, and three separate statistical analyses to investigate the relationship between RMR and organ morphology were performed: (i) employing individual regression analysis with each tissue component as a separate predictor against RMR; (ii) individual regression analysis with residual organ mass against residual RMR (i.e. with strain, sex and body mass effects removed); and (iii) pooling of some organ masses into functional groupings to reduce the number of predictors. Liver mass was the most significant morphological trait linked to differences in RMR. Small intestine length was significantly greater in the high-intake line; however, no difference was observed between strains in the dry mass of this organ, and there was no evidence to associate variability in the mass of the alimentary tract with variability in RMR. The effects of strain on RMR independent of the effect on body mass were consistent with the anticipated effect from the strain differences in the size of the liver.

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.

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