scholarly journals Daily Energy Budgets of Avian Embryos: The Paradox of the Plateau Phase in Egg Metabolic Rate

1998 ◽  
Vol 71 (2) ◽  
pp. 147-156 ◽  
Author(s):  
Maurine W. Dietz ◽  
Meep van Kampen ◽  
Marcel J. M. van Griensven ◽  
Sijmen van Mourik
1996 ◽  
Vol 74 (12) ◽  
pp. 2131-2142 ◽  
Author(s):  
Joep J. de Leeuw

Metabolic studies on freely diving birds and mammals are reviewed and allometric relations of diving costs are presented. A distinction can be made between three different types of diving costs: (1) metabolic rate during submergence, relevant in estimating aerobic dive limits, (2) average metabolic rate during diving and breathing intervals (MRd), and (3) diving costs as the excess over resting costs (EDC). EDC is the most comprehensive measure, integrating energy costs over entire dive series with subsequent longer term recovery from heat loss or anaerobic metabolism. Respirometry experiments with tufted duck (Aythya fuligula) diving in a 5.7 m deep indoor tank demonstrated that in this species diving costs, expressed as EDC, increased at lower water temperatures. MRd was not significantly related to temperature, and probably reflects only the hydrodynamic and not the thermoregulatory component of diving costs. In general, the usual practice of measuring metabolic costs only during diving activity seems insufficient to estimate the total costs of diving. Studies that include longer term recovery (e.g., doubly labelled water measurements over entire foraging trips) yield more complete estimates of diving costs. To take diving costs into account in an animal's energy budget, estimates of EDC are more appropriate than MRd.


1995 ◽  
Vol 73 (3) ◽  
pp. 452-457 ◽  
Author(s):  
Karol A. Worden ◽  
Peter J. Pekins

Winter is a critical time of year for white-tailed deer (Odocoileus virginianus) in northern regions because their food consumption does not meet their daily energy demands. We measured feed intake, fasting metabolic rate (FMR), and body composition of five captive adult female white-tailed deer from September 1991 through March 1992 in New Hampshire to investigate the relationships between FMR and feed intake to fat deposition and mobilization. Deuterium oxide dilution was used to estimate monthly body composition, indirect respiration calorimetry was used to measure monthly FMR, and metabolizable energy intake (MEI) was calculated from daily feed intake. Mean percent body fat increased from 9.1 ± 1.5 to 24.9 ± 4.4% from September to December, and then declined through March. Mean percent body protein did not change during the study (range 20–21%). Mean MEI peaked during September and October (171.9 ± 8.1 and 168.7 ± 10.3 kcal∙kg body mass−0.75∙d−1, respectively), and declined 54% by February. Mean FMR ranged from 79 to 90 from October through March. Correlations between MEI or FMR and change in body fat were weak. It was estimated that intake rates of free-ranging deer were only 90–110% of winter FMR, and that deer with 20% body fat could balance their daily energy expenditure (1.7 × FMR) with fat stores for about 3 months, or the period of time during which MEI was depressed in captive deer.


Science ◽  
2014 ◽  
Vol 346 (6205) ◽  
pp. 79-81 ◽  
Author(s):  
David M. Scantlebury ◽  
Michael G. L. Mills ◽  
Rory P. Wilson ◽  
John W. Wilson ◽  
Margaret E. J. Mills ◽  
...  

Population viability is driven by individual survival, which in turn depends on individuals balancing energy budgets. As carnivores may function close to maximum sustained power outputs, decreased food availability or increased activity may render some populations energetically vulnerable. Prey theft may compromise energetic budgets of mesopredators, such as cheetahs and wild dogs, which are susceptible to competition from larger carnivores. We show that daily energy expenditure (DEE) of cheetahs was similar to size-based predictions and positively related to distance traveled. Theft at 25% only requires cheetahs to hunt for an extra 1.1 hour per day, increasing DEE by just 12%. Therefore, not all mesopredators are energetically constrained by direct competition. Other factors that increase DEE, such as those that increase travel, may be more important for population viability.


2002 ◽  
Vol 205 (19) ◽  
pp. 2963-2970 ◽  
Author(s):  
Leonardo D. Bacigalupe ◽  
Francisco Bozinovic

SUMMARY Physiological limitations affect an organism's capacity to acquire and expend energy over long periods of activity. These limitations could be related to the central machinery used for acquiring, processing and allocating energy, or by the energy-consuming machinery. Another possibility is that the capacities of central and peripheral organs and tissues are co-adjusted,implying an optimized design. Given the important consequences that rates of energy expenditure have on many ecological aspects of animal life, we need to understand which factors impose ceilings on sustained metabolic rate. Ceilings on sustainable energy expenditure represent the limit below which all the activities performed by an individual must occur. There have been many studies of design constraints on energy budgets, but the different procedures used to identify the type of physiological limitation do not necessarily resolve which factors actually impose metabolic ceilings in small mammals, which precludes a clear understanding of the ecological and evolutionary consequences of design constraints on energy budgets. We propose that the following steps are necessary to identify the physiological limits on sustained metabolic rate:(1) combining peak energy demands to differentiate a central limitation from a peripheral limitation; (2) pushing the animals to their physiological limits(e.g. asymptotic food intake); (3) testing for a central excess capacity (if the limit is set peripherally), or a peripheral excess capacity (if there is a central limitation); (4) utilizing different levels of energy demand to test for symmorphosis.


2012 ◽  
Vol 97 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Phillipa Caudwell ◽  
Graham Finlayson ◽  
Catherine Gibbons ◽  
Mark Hopkins ◽  
Neil King ◽  
...  

2012 ◽  
Vol 216 (3) ◽  
pp. 418-426 ◽  
Author(s):  
V. Careau ◽  
D. Reale ◽  
D. Garant ◽  
F. Pelletier ◽  
J. R. Speakman ◽  
...  

The Condor ◽  
2000 ◽  
Vol 102 (3) ◽  
pp. 635-644 ◽  
Author(s):  
Sheldon J. Cooper

Abstract I used behavioral, meteorological, and laboratory metabolism data to calculate daily energy expenditure (DEE) in seasonally acclimatized Mountain Chickadees (Poecile gambeli) and Juniper Titmice (Baeolophus griseus). Analyses of laboratory metabolic data revealed that foraging energy requirements were not significantly higher than alert perching energy requirements. Respective DEE of chickadees and titmice were 48.8 kJ day−1 and 48.3 kJ day−1 in summer and 66.3 kJ day−1 and 98.7 kJ day−1 in winter. DEE as a multiple of basal metabolic rate (BMR) was 2.31 in summer chickadees and 1.91 in summer titmice. DEE was 2.70 times BMR in winter chickadees and 3.43 times BMR in winter titmice. The marked increase in calculated DEE in winter birds compared to summer is in contrast to a pattern of increased DEE in the breeding season for several avian species. These data suggest that winter may be a period of even greater stringency for small birds than previously believed.


1991 ◽  
Vol 69 (10) ◽  
pp. 2548-2555 ◽  
Author(s):  
Paul Stapp ◽  
Peter J. Pekins ◽  
William W. Mautz

The southern flying squirrel (Glaucomys volans) forms large aggregations inside nest-lined tree cavities to reduce exposure to winter temperatures. We measured oxygen consumption of individuals and grouped flying squirrels in Plexiglas and nest-box chambers in New Hampshire to determine savings provided by huddling and nest construction. Because G. volans breeds during late winter, we also measured energy expenditure of females during gestation and lactation. These data were used to construct daily energy budgets for flying squirrels during winter and to investigate the relationship between this species' cold tolerance and its current distribution. Flying squirrels had lower basal metabolism (0.95 cm3 O2∙g−1∙h−1) and rate of heat loss (0.11 cm3 O2∙g−1∙h−1∙ °C−1) than predicted according to mass. Peak reproductive costs (1 week postparturition) were 170% of nonbreeding requirements. At 9 °C, huddling in groups of three and six reduced energy expenditure by 27 and 36%, respectively. Compared with individuals without nests, nest insulation decreased heat loss by 37% for single squirrels and reduced lower critical temperature from 26.5 to 12.2 °C for groups of six. As estimated from our budget, aggregating reduces winter daily energy expenditure by 26–33%. At the northern range boundary, daily expenditure for squirrels using both aggregations and nests (2.5 times basal metabolism) and for females during peak lactation (3.9 times basal metabolism) was similar to estimates of maximal daily energy expenditure in the literature. We speculate that additional thermoregulatory costs and the decreased abundance of hard mast for winter caches prevent G. volans from occupying areas north of its current distribution.


1965 ◽  
Vol 27 (5) ◽  
pp. 363-370
Author(s):  
Jacob Verduin
Keyword(s):  

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