scholarly journals Reproductive energetics of adult male yellow-bellied marmots (Marmota flaviventris)

1995 ◽  
Vol 73 (10) ◽  
pp. 1791-1797 ◽  
Author(s):  
Carmen M. Salsbury ◽  
Kenneth B. Armitage
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Adult Male ◽  
Reproductive Investment ◽  
High Energy ◽  
Male Reproductive Success ◽  
Metabolic Rates ◽  
Marmota Flaviventris ◽  
Term Survival ◽  
Active Season

We examined the energy expenditure of adult male yellow-bellied marmots (Marmota flaviventris) and its relationship to various female-defense characteristics critical to male reproductive success. Resting metabolic rates of males were estimated in the laboratory via oxygen-consumption analysis, and field metabolic rates were estimated using a doubly labeled water technique. Male home-range size, number of females defended by males, dispersion of females in the habitat, and date into the active season were considered to be predictors of male energy expenditure in excess of maintenance costs (field metabolic rate minus resting metabolic rate). Energy expenditure was best explained by a defensibility index based on the number and dispersion of females defended; expenditure increased with number and dispersion of females. Energy expenditure increased with date into the active season. Environmental constraints on male activity during the mating season may have led to a shift in male reproductive investment to later in the season, when intruder pressure by conspecifics increased. No short-term survival costs were associated with high energy expenditure; males appeared to engage in reproductive behaviors congruent with their physiological capabilities.

Metabolic Rate and Energy Expenditure of the Spiny Dogfish, Squalus acanthias

1978 ◽  
Vol 35 (6) ◽  
pp. 816-821 ◽  
Author(s):  
J. R. Brett ◽  
J. M. Blackburn
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Key Words ◽  
Swimming Performance ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Metabolic Rates ◽  
Performance Curve ◽  
Power Performance ◽  
General Energy

The metabolic rate of spiny dogfish, Squalus acanthias, was determined in both a tunnel respirometer and a large, covered, circular tank (mass respirometer). Swimming performance was very poor in the respirometer, so that a power–performance curve could not be established. Instead, resting metabolic rates were determined, with higher rates induced by causing heavy thrashing (active metabolism). Routine metabolic rates were measured for the spontaneous activity characterizing behavior in the circular tank. For fish of 2 kg mean weight, the metabolic rates at 10 °C were 32.4 ± 2.6 SE (resting), 49.2 ± 5.0 SE (routine), and 88.4 ± 4.6 SE (active) mg O2∙kg−1∙h−1. Assuming that the routine rate represents a general energy expenditure in nature, this is equivalent to metabolizing about 3.8 kcal∙kg−1∙d−1 (15.9 × 103 J∙kg−1∙d−1). Key words: dogfish, metabolic rates, energetics, respiration

Metabolic strategies for winter survival by Svalbard reindeer

1993 ◽  
Vol 71 (9) ◽  
pp. 1787-1792 ◽  
Author(s):  
L. C. Cuyler ◽  
N. A. Øritsland
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Energy Requirement ◽  
Resting Metabolic Rate ◽  
Thermal Conductance ◽  
Activity Budget ◽  
Survival Strategies ◽  
Metabolic Rates ◽  
Energy Expenditures ◽  
Svalbard Reindeer

Lying and standing metabolic rates were determined for two tame Svalbard reindeer while the animals were in their winter lethargic state during January and February. Mean nonfasting metabolic rates for the 59-kg animals were 1.25 W∙kg−1 for lying and 1.64 W∙kg−1 for standing at rest. So the metabolic rate for standing at rest was about 1.3 times the lying resting metabolic rate (RMR). For Svalbard reindeer the lying RMR was 66–78% of the values for other reindeer/caribou, and was 78–89% of the predicted value. The standing RMR was 44–88% of the values from other reindeer/caribou. Total body thermal conductance was 1.95 ± 0.17 W∙°C−1 for lying and 3.08 ± 0.77 W∙°C−1 for standing at rest. The daily energy expenditure during winter was estimated to be about 9654 kJ∙day−1 or 112 W, and was 1.5 times Kleiber's predicted basal metabolic rate. By remaining lying 45% of the time rather than 35% Svalbard reindeer may conserve the equivalent of about 15 days' energy requirement over the winter. With locomotion at 2% of the winter daily activity budget, the Svalbard reindeer conserve about 21 days' energy expenditure, more than that if locomotion were 8.2% of the budget as in caribou (Boertje 1985). Thus, their low energy expenditures for lying and standing and their sedentary activity budget may be considered energy-saving and survival strategies. It is possible that disturbances, which cause the animals to increase activity, may have a detrimental effect on their overall winter energy balance.

scholarly journals Basal metabolic rate and energy expenditure or rural farmers in Magubike village, Kilosa district, Tanzania

2013 ◽  
Vol 13 (59) ◽  
pp. 8128-8138
Author(s):  
HN Ocan ◽  
◽  
JL Kinabo ◽  
PS Mamiro ◽  
CN Nyaruhucha
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Total Energy ◽  
Basal Metabolic Rate ◽  
Energy Requirement ◽  
High Energy ◽  
Activity Level ◽  
Rural Farmers ◽  
The Mean

Measurement of basal metabolic rate (BMR) provides an important baseline for the determination of an individual’s total energy requirement. The study sought to establish human energy expenditure of rural farmers in Magubike village in Tanzania, through determination of BMR, physical activity level (PAL) and total energy expenditure (TEE). In addition, the study intended to provide an indication of the level of energy requirement for the rural people of Tanzania. The objective of the study was to determine energy expenditure of farmers in comparison to the mean caloric intake per capita and the WHO/FAO recommended energy requirements for developing countries. A cross-sectional study design involving 33 male and 31 female farmers was conducted on randomly selected households. Basal Metabolic rate and household activities were measured by indirect calorimetry, using the Douglas bag technique. Physical activity Level was measured by twenty-four hour activity diary and TEE calculated as a product of BMR and PAL. Men’s BMR was 4.7 MJ/day while that of women was 4.3 MJ/day. Farmers mean PAL was 2.20 ± 0.25 in men and 2.05 ± 0.23 in females and TEE was 10.24 MJ/day in men and 8.57 MJ/day in women. Both BMR and TEE were higher in men than in women. The measured energy expenditure for digging and weeding were 1.57 ± 0.3 kJ/min; 1.36 ± 0.31kJ/min in men and 1.58 ± 0.3 kJ/min; 1.49 ± 0.33 kJ/min in women. It was revealed that total energy expenditure of farmers in Magubike village was high with the values being above the mean daily calorie requirement per capita for Tanzania (8.15 MJ/day) but within the WHO/FAO recommended energy requirements (11.26 MJ/day) for developing countries. High energy expenditure was attributed to high energy levels spent in farm activities which were manual and labour intensive. This is likely to be the situation in many rural areas of Tanzania. More work on measurement of costs of farm activities and farmers work capacity are necessary to provide recommendations on energy needs of rural farmers.

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.

Seasonal variation in energy expenditure, water flux and food consumption of Arabian oryx Oryx leucoryx

2001 ◽  
Vol 204 (13) ◽  
pp. 2301-2311 ◽  
Author(s):  
Joseph B. Williams ◽  
Stéphane Ostrowski ◽  
Eric Bedin ◽  
Khairi Ismail
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Body Mass ◽  
Water Loss ◽  
Arid Zone ◽  
Water Flux ◽  
Metabolic Rates ◽  
Free Living ◽  
Evaporative Water ◽  
Arabian Oryx

SUMMARY We report on the energy expenditure and water flux, measured in the laboratory and in the field, of the Arabian oryx Oryx leucoryx, the largest desert ruminant for which measurements of the field metabolic rate of free-living individuals have been made using doubly labeled water. Prior to extirpation of this species in the wild in 1972, conservationists sequestered a number of individuals for captive breeding; in 1989, oryx were reintroduced in Saudi Arabia into Mahazat as-Sayd (2244km2). Apart from small pools of water available after rains, oryx do not have free-standing water available for drinking and therefore rely on grasses that they eat for preformed water intake as well as their energy needs. We tested whether oryx have a reduced fasting metabolic rate and total evaporative water loss (TEWL) in the laboratory, as do some other arid-adapted mammals, and whether oryx have high field metabolic rates (FMRs) and water influx rates (WIRs), as predicted by allometric equations for large arid-zone mammals. We measured FMR and WIR during the hot summer, when plant moisture content was low and ambient temperatures were high, and after winter rains, when the water content of grasses was high. For captive oryx that weighed 84.1kg, fasting metabolic rate averaged 8980kJday−1, 16.7% lower than predictions for Artiodactyla. Our own re-analysis of minimal metabolic rates among Artiodactyla yielded the equation: logV̇O2=−0.153+0.758logM, where V̇O2 is the rate of oxygen uptake in lh−1 and M is body mass in kg. Fasting metabolic rate of oryx was only 9.1% lower than predicted, suggesting that they do not have an unusually low metabolic rate. TEWL averaged 870.0mlday−1, 63.9% lower than predicted, a remarkably low value even compared with the camel, but the mechanisms that contribute to such low rates of water loss remain unresolved. For free-living oryx, FMR was 11076kJday−1 for animals with a mean body mass of 81.5kg during summer, whereas it was 22081kJday−1 for oryx in spring with a mean body mass of 89.0kg, values that were 48.6% and 90.4% of allometric predictions, respectively. During summer, WIR averaged 1310mlH2Oday−1, whereas in spring it was 3438mlH2Oday−1. Compared with allometric predictions, WIR was 76.9% lower than expected in summer and 43.6% lower in spring. We found no evidence to support the view that the WIR of large desert ungulates is higher than that of their mesic counterparts. On the basis of the WIR of the oryx averaged over the year and the water contents of plants in their diet, we estimated that an oryx consumes 858kg of dry matter per year.

Simulated weightlessness alters the nycthemeral distribution of energy expenditure in rats

2001 ◽  
Vol 204 (23) ◽  
pp. 4107-4113
Author(s):  
Stéphane Blanc ◽  
Alain Géloën ◽  
Sylvie Normand ◽  
Claude Gharib ◽  
Laurence Somody
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Male Rats ◽  
Metabolic Rates ◽  
Tail Suspension ◽  
Simulated Weightlessness ◽  
Basal Energy Expenditure ◽  
The Cost

SUMMARY The energy metabolism adaptations to simulated weightlessness in rats by hindlimb tail suspension are unknown. 12 male rats were assigned to 7 days of isolation, 7 days of habituation to the suspension device, 10 days of simulated weightlessness, and 3 days of recovery. The 24-hour energy expenditure was measured by continuous indirect calorimetry. We calculated the 12-hour energy expenditure during the active (night) and inactive (day) periods, the minimal observed metabolic rates with the day values taken as an index of the basal metabolic rate, and the non-basal energy expenditure representing the cost of physical activity plus the diet-induced thermogenesis. Suspension did not change the mean 24-hour energy expenditure (360.8±15.3 J min–1 kg–0.67), but reduced the night/day difference by 64 % (P<0.05) through a concomitant drop in night-energy expenditure and increase in day values. The difference between night and day minimal metabolic rates was reduced by 81 % (P<0.05), and the transient rise in day values suggests an early and moderate basal metabolic rate increase (9 %). An overall 19 % reduction in non-basal energy expenditure was observed during simulated weightlessness (P<0.05), which was mainly attributable to a reduction in the cost of physical activity. 3 days of recovery restored the night/day differences but increased the 24-hour energy expenditure by 10 % (P<0.05). In conclusion, hindlimb tail suspension in rats did not alter the 24-hour energy expenditure, but it transiently increased the basal metabolic rate, and altered both the energy expended on physical activity and the nycthemeral distribution of motor activity. These data suggest that the circadian rhythms of energy expenditure are affected during simulated weightlessness.

scholarly journals Differences in postprandial responses to fat and carbohydrate loads in habitual high and low fat consumers (phenotypes)

2002 ◽  
Vol 88 (2) ◽  
pp. 125-132 ◽  
Author(s):  
J. E. Blundell ◽  
J. Cooling ◽  
N. A. King
Keyword(s):  
Heart Rate ◽  
Energy Expenditure ◽  
Metabolic Rate ◽  
Fat Oxidation ◽  
High Energy ◽  
High Fat ◽  
Low Fat ◽  
Carbohydrate Ingestion ◽  
Carbohydrate Load ◽  
Male Subjects

The present study investigated metabolic responses to fat and carbohydrate ingestion in lean male individuals consuming an habitual diet high or low in fat. Twelve high-fat phenotypes (HF) and twelve low-fat phenotypes (LF) participated in the study. Energy intake and macronutrient intake variables were assessed using a food frequency questionnaire. Resting (RMR) and postprandial metabolic rate and substrate oxidation (respiratory quotient; RQ) were measured by indirect calorimetry. HF had a significantly higher RMR and higher resting heart rate than LF. These variables remained higher in HF following the macronutrient challenge. In all subjects the carbohydrate load increased metabolic rate and heart rate significantly more than the fat load. Fat oxidation (indicated by a low RQ) was significantly higher in HF than in LF following the fat load; the ability to oxidise a high carbohydrate load did not differ between the groups. Lean male subjects consuming a diet high in fat were associated with increased energy expenditure at rest and a relatively higher fat oxidation in response to a high fat load; these observations may be partly responsible for maintaining energy balance on a high-fat (high-energy) diet. In contrast, a low consumer of fat is associated with relatively lower energy expenditure at rest and lower fat oxidation, which has implications for weight gain if high-fat foods or meals are periodically introduced to the diet.

scholarly journals Fasting in the ureotelic Lake Magadi tilapia, Alcolapia grahami, does not reduce its high metabolic demand, increasing its vulnerability to siltation events

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Gudrun De Boeck ◽  
Chris M Wood ◽  
Kevin V Brix ◽  
Amit K Sinha ◽  
Victoria Matey ◽  
...  
Keyword(s):  
Gene Expression ◽  
Metabolic Rate ◽  
Food Source ◽  
Swimming Performance ◽  
Aerobic Performance ◽  
Metabolic Rates ◽  
Term Survival ◽  
Ammonia Metabolism ◽  
Lake Magadi ◽  
Alcolapia Grahami

Abstract Lake Magadi, Kenya, is one of the most extreme aquatic environments on Earth (pH~10, anoxic to hyperoxic, high temperatures). Recently, increased water demand and siltation have threatened the viable hot springs near the margins of the lake where Alcolapia grahami, the only fish surviving in the lake, live. These Lake Magadi tilapia largely depend on nitrogen-rich cyanobacteria for food and are 100% ureotelic. Their exceptionally high aerobic metabolic rate, together with their emaciated appearance, suggests that they are energy-limited. Therefore, we hypothesized that during food deprivation, Magadi tilapia would economize their energy expenditure and reduce metabolic rate, aerobic performance and urea-N excretion. Surprisingly, during a 5-day fasting period, routine metabolic rates increased and swimming performance (critical swimming speed) was not affected. Urea-N excretion remained stable despite the lack of their N-rich food source. Their nitrogen use switched to endogenous sources as liver and muscle protein levels decreased after a 5-day fast, indicating proteolysis. Additionally, fish relied on carbohydrates with lowered muscle glycogen levels, but there were no signs indicating use of lipid stores. Gene expression of gill and gut urea transporters were transiently reduced as were gill rhesus glycoprotein Rhbg and Rhcg-2. The reduction in gill glutamine synthetase expression concomitant with the reduction in Rh glycoprotein gene expression indicates reduced nitrogen/ammonia metabolism, most likely decreased protein synthesis. Additionally, fish showed reduced plasma total CO2, osmolality and Na+ (but not Cl−) levels, possibly related to reduced drinking rates and metabolic acidosis. Our work shows that Lake Magadi tilapia have the capacity to survive short periods of starvation which could occur when siltation linked to flash floods covers their main food source, but their seemingly hardwired high metabolic rates would compromise long-term survival.

scholarly journals Metabolic traits in brown trout (Salmo trutta) vary in response to food restriction and intrinsic factors

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Louise C Archer ◽  
Stephen A Hutton ◽  
Luke Harman ◽  
W Russell Poole ◽  
Patrick Gargan ◽  
...  
Keyword(s):  
Life History ◽  
Metabolic Rate ◽  
Intraspecific Variation ◽  
Brown Trout ◽  
Environmental Conditions ◽  
Food Restriction ◽  
Metabolic Rates ◽  
Intrinsic Factors ◽  
Metabolic Traits ◽  
Food Conditions

Abstract Metabolic rates vary hugely within and between populations, yet we know relatively little about factors causing intraspecific variation. Since metabolic rate determines the energetic cost of life, uncovering these sources of variation is important to understand and forecast responses to environmental change. Moreover, few studies have examined factors causing intraspecific variation in metabolic flexibility. We explore how extrinsic environmental conditions and intrinsic factors contribute to variation in metabolic traits in brown trout, an iconic and polymorphic species that is threatened across much of its native range. We measured metabolic traits in offspring from two wild populations that naturally show life-history variation in migratory tactics (one anadromous, i.e. sea-migratory, one non-anadromous) that we reared under either optimal food or experimental conditions of long-term food restriction (lasting between 7 and 17 months). Both populations showed decreased standard metabolic rates (SMR—baseline energy requirements) under low food conditions. The anadromous population had higher maximum metabolic rate (MMR) than the non-anadromous population, and marginally higher SMR. The MMR difference was greater than SMR and consequently aerobic scope (AS) was higher in the anadromous population. MMR and AS were both higher in males than females. The anadromous population also had higher AS under low food compared to optimal food conditions, consistent with population-specific effects of food restriction on AS. Our results suggest different components of metabolic rate can vary in their response to environmental conditions, and according to intrinsic (population-background/sex) effects. Populations might further differ in their flexibility of metabolic traits, potentially due to intrinsic factors related to life history (e.g. migratory tactics). More comparisons of populations/individuals with divergent life histories will help to reveal this. Overall, our study suggests that incorporating an understanding of metabolic trait variation and flexibility and linking this to life history and demography will improve our ability to conserve populations experiencing global change.

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