scholarly journals Metabolic rates of aggressive/submissive phenotypes are colour blind in the polymorphic Gouldian finch

Author(s):  
William A. Buttemer ◽  
Vincent Careau ◽  
Mark A. Chappell ◽  
Simon C. Griffith

Evidence from a number of species suggests behaviours associated with social rank are positively correlated with metabolic rate. These studies, however, are based on metabolic measurements of isolated individuals, thereby ignoring potential effects of social interactions on metabolic rates. Here, we characterised three pertinent metabolic indices in the two predominant genetic colour morphs of the Gouldian finch (Erythrura gouldiae): diurnal resting metabolic rate (RMR), nocturnal basal metabolic rate (BMR), and exercise-induced maximal metabolic rate (MMR). Research reveals red-headed morphs consistently dominate the less aggressive black-headed morphs and the two morphs to differ in other behavioural and physiological traits. We measured daytime RMR of intermorph naïve birds (first-year virgin males maintained in total isolation from opposite colour morphs) and their metabolic responses to viewing a socially unfamiliar bird of each colour. Subsequently each bird was placed in a home cage with an opposite colour morph (intermorph exposed) and the series of measurements repeated. Daytime RMR was indistinguishable between the two morphs, whether intermorph naïve or intermorph exposed. However, both red- and black-headed birds showed a greater short-term increase in metabolic rate when viewing an unfamiliar red-headed bird than when seeing a black-headed bird, but only when intermorph naïve. Measurements of BMR and exercise-induced MMR did not differ between the two morphs, and consequently aerobic scope was indistinguishable between them. We propose that the suite of behavioural differences between these two sympatric morphs are functionally complementary and represent evolutionary stable strategies permitting establishment of dominance status in the absence of metabolic costs.

2020 ◽  
Vol 158 (5) ◽  
pp. 431-437
Author(s):  
Michael Kam ◽  
Shaher El-Meccawi ◽  
Arieh Brosh ◽  
A. Allan Degen

AbstractSheep are grazers and goats are intermediate feeders. By employing O2 consumption and heart rate measurements, resting metabolic rate (RMR) and field metabolic rate (FMR) were determined in four male fat-tailed Awassi sheep (44.0 ± 3.94) and four male Baladi goats (35.5 ± 5.42 kg) that were co-grazing natural pasture in the Negev Desert. There were 67.7 ± 3.75 g DM/m2 of herbaceous vegetation biomass, which was rapidly becoming senescent and more fibrous. We hypothesized that FMR of these desert-adapted ruminants would be relatively low when compared to other sheep and goat breeds, as animals in arid areas tend to have low metabolic rates. Both sheep (n = 6) and goats (n = 6) foraged 71% of the allotted 11 h free-pasture period; however, sheep grazed more than goats (P < 0.001); whereas goats browsed more than sheep (P < 0.001). RMR was higher (P = 0.007) in sheep than in goats (529 ± 23.5 v. 474 ± 25.4 kJ/kg0.75 BW/d), but FMR did not differ between species (618 ± 55.7 v. 613 ± 115.2 kJ/kg0.75 BW/d). In addition, the cost of activities, as a proportion of FMR, did not differ between sheep and goats; FMR increased by 89 kJ/kg0.75 BW/d or 17% in sheep and by 138 kJ/kg0.75 BW/d or 29% in goats. In comparing FMRs of sheep and goats in this study with these species in other studies, differences were inconsistent and, therefore, our hypothesis was not supported.


1986 ◽  
Vol 66 (4) ◽  
pp. 937-944 ◽  
Author(s):  
M. OKAMOTO ◽  
J. B. ROBINSON ◽  
R. J. CHRISTOPHERSON ◽  
B. A. YOUNG

Resting and summit metabolic rates were measured in 13 newborn (2.5–15 h old) male Holstein calves exposed to warm and cold tempertures in a water immersion system. Six calves were bottle fed 1 kg of colostrum 30 min before the measurements commenced. In the remaining seven calves, colostrum was withheld until after the end of the measurement period. There were no significant effects of colostrum feeding on resting or summit metabolic rates or the time required for rectal temperature to drop to 35 °C when the calves were immersed in cold water. The time required for rectal temperature to drop to 35 °C increased as the body weight of the calves increased; for each kilogram additional body weight, cooling was delayed for an extra 2.9 min. The resting metabolic rate averaged for both feeding treatments was 2.0 ± 0.1 W kg−1 while mean rectal temperature was 39.1 ± 0.2 °C. Mean summit metabolic rate was 7.2 ± 0.4 W kg−1 and occurred at a mean rectal temperature of 35.4 ± 0.3 °C. The average ratio of the summit to resting metabolic rate was 3.7 ± 0.2. Cooling via water immersion was associated with increases in plasma levels of glucose and free fatty acids. The feeding of 1 kg of colostrum 30 min prior to exposure to acute cold did not improve the apparent resistance of the calves to hypothermia. Key words: Newborn calf, summit metabolism, cold tolerance


1993 ◽  
Vol 71 (9) ◽  
pp. 1787-1792 ◽  
Author(s):  
L. C. Cuyler ◽  
N. A. Øritsland

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.


2020 ◽  
Author(s):  
Jan S Boratyński ◽  
Karolina Iwińska ◽  
Paulina A Szafrańska ◽  
Piotr Chibowski ◽  
Wiesław Bogdanowicz

Abstract Small mammals that are specialists in homeothermic thermoregulation reduce their self-maintenance costs of normothermy to survive the winter. By contrast, heterothermic ones that are considered generalists in thermoregulation can lower energy expenditure by entering torpor. It is well known that different species vary the use of their strategies to cope with harsh winters in temperate zones; however, little is still known about the intraspecific variation within populations and the associated external and internal factors. We hypothesized that yellow-necked mice Apodemus flavicollis decrease their resting metabolic rate (RMR) from autumn to winter, and then increase it during spring. However, since the alternative for seasonal reduction of RMR could be the development of heterothermy, we also considered the use of this strategy. We measured body mass (mb), RMR, and body temperature (Tb) of mice during two consecutive years. In the first year, mice decreased whole animal RMR in winter, but did not do so in the second year. All mice entered torpor during the second winter, whereas only a few did so during the first one. Mice showed a continuous increase of mb, which was steepest during the second year. The relationship between RMR and mb varied among seasons and years most likely due to different mouse development stages. The mb gain at the individual level was correlated positively with RMR and heterothermy. This indicates that high metabolism in winter supports the growth of smaller animals, which use torpor as a compensatory mechanism. Isotope composition of mice hair suggests that in the first year they fed mainly on seeds, while in the second, they likely consumed significant amounts of less digestible herbs. The study suggests that the use of specialist or generalist thermoregulatory strategies can differ with environmental variation and associated differences in developmental processes.


1997 ◽  
Vol 75 (11) ◽  
pp. 1781-1789 ◽  
Author(s):  
Patrice Boily ◽  
David M. Lavigne

Resting metabolic rate (RMR) data obtained from five juvenile and three adult female grey seals (Halichoerus grypus) in captivity over a period of 3.5 years were examined for developmental and seasonal changes. Three juveniles exhibited a significant relationship between log10 RMR and log10 mass, with individual slopes ranging from 0.42 to 1.62. Two of these exhibited a significant relationship between log10 RMR and log10 age. The remaining two juveniles and the three adults exhibited no significant relationship between RMR and body mass. With increasing size and age, RMRs of juveniles approached predicted values for adult mammals, but the large variation made it difficult to establish the precise age at which they achieved an adult-like RMR. RMRs of adults and juveniles exhibited marked seasonal changes. In juveniles, seasonal changes in RMR were limited to the annual moult, when the average RMR was 35% higher than during the rest of the year. In adults, changes in RMR were not limited to the time of the annual moult; rather, RMR was lower (by up to 50%) in the summer than during other seasons.


1959 ◽  
Vol 37 (3) ◽  
pp. 473-478 ◽  
Author(s):  
O. Héroux ◽  
F. Depocas ◽  
J. S. Hart

Physiological adjustments to cold temperature have been compared in white rats exposed either to the outdoor fluctuating environmental conditions or to the indoor constant temperature conditions. While the metabolic adjustments such as increased peak metabolism and decreased shivering were similar in outdoor and indoor rats exposed to cold, the adjustments in insulation and thermoneutral metabolic rates were quite different. The pelage insulation increased in the rats kept outside during the winter but remained unchanged in the rats kept in a constant temperature room maintained at 6 °C. The resting metabolic rate measured at 30 °C increased in the 6 °C acclimated rats but not in the winter-exposed animals. Over the temperature range +30 °C to −15 °C, while the indoor cold-acclimated rats had a higher metabolic rate than their controls acclimated to 30 °C, the winter rats had a lower metabolism than their summer controls.


2000 ◽  
Vol 203 (6) ◽  
pp. 1003-1016 ◽  
Author(s):  
M.J. Donohue ◽  
D.P. Costa ◽  
M.E. Goebel ◽  
J.D. Baker

Young pinnipeds, born on land, must eventually enter the water to feed independently. The aim of this study was to examine developmental factors that might influence this transition. The ontogeny of metabolic rate and thermoregulation in northern fur seal, Callorhinus ursinus, pups was investigated at two developmental stages in air and water using open-circuit respirometry. Mean in-air resting metabolic rate (RMR) increased significantly from 113+/−5 ml O(2)min(−)(1) (N=18) pre-molt to 160+/−4 ml O(2)min(−)(1) (N=16; means +/− s.e.m.) post-molt. In-water, whole-body metabolic rates did not differ pre- and post-molt and were 2.6 and 1.6 times in-air RMRs respectively. Mass-specific metabolic rates of pre-molt pups in water were 2.8 times in-air rates. Mean mass-specific metabolic rates of post-molt pups at 20 degrees C in water and air did not differ (16.1+/−1.7 ml O(2)min(−)(1)kg(−)(1); N=10). In-air mass-specific metabolic rates of post-molt pups were significantly lower than in-water rates at 5 degrees C (18.2+/−1.1 ml O(2)min(−)(1)kg(−)(1); N=10) and 10 degrees C (19.4+/−1.7 ml O(2)min(−)(1)kg(−)(1); N=10; means +/− s.e.m.). Northern fur seal pups have metabolic rates comparable with those of terrestrial mammalian young of similar body size. Thermal conductance was independent of air temperature, but increased with water temperature. In-water thermal conductance of pre-molt pups was approximately twice that of post-molt pups. In-water pre-molt pups matched the energy expenditure of larger post-molt pups while still failing to maintain body temperature. Pre-molt pups experience greater relative costs when entering the water regardless of temperature than do larger post-molt pups. This study demonstrates that the development of thermoregulatory capabilities plays a significant role in determining when northern fur seal pups enter the water.


Paleobiology ◽  
2019 ◽  
Vol 45 (02) ◽  
pp. 317-330 ◽  
Author(s):  
Jorge Cubo ◽  
Nour-Eddine Jalil

AbstractThis paper is aimed at constraining the phylogenetic frame of the acquisition of endothermy by Archosauromorpha. We analyzed the bone histology of Azendohsaurus laaroussii. Stylopodial and zeugopodial bones show three tissue types: (1) avascular lamellar zonal bone formed at low growth rates; (2) a scaffold of parallel-fibered bone containing either small primary osteons or simple vascular canals; and (3) fibrolamellar bone formed at high growth rates. We used quantitative histology to infer the thermometabolic regime of this taxon. We define endothermy as the presence of any mechanism of nonshivering thermogenesis that increases both body temperature and resting metabolic rate. Thus, estimating the resting metabolic rate of an extinct organism may be a good proxy to infer its thermometabolic regime (endothermy vs. ectothermy). High resting metabolic rates have been shown to be primitive for the clade Prolacerta–Archosauriformes. Therefore, we inferred the resting metabolic rates of A. laaroussii, a sister group of this clade, and of 14 extinct related taxa, using phylogenetic eigenvector maps. All the inferences obtained are included in the range of variation of resting metabolic rates measured in mammals and birds, so we can reasonably assume that all these taxa (including Azendohsaurus) were endotherms. A parsimony optimization of the presence of endothermy on a phylogenetic tree of tetrapods shows that this derived character state was acquired by the last common ancestor of the clade Azendohsaurus–Archosauriformes and that there is a reversion in Crocodylia.


2020 ◽  
Vol 16 (4) ◽  
pp. 20190825
Author(s):  
Yan Huang ◽  
Shijian Fu ◽  
Steven J. Cooke ◽  
Jigang Xia

Metabolic rates are typically thought to have important influences on fitness and more broadly be relevant to the ecology and evolution of animals. Previous studies demonstrate that metabolic rates are repeatable to a certain extent under constant conditions, but how social conditions influence the repeatability of metabolic rate remains largely unknown. In this study, we investigated the repeatability of resting metabolic rate (RMR) in the highly social crucian carp ( Carassius auratus ) after being socially separated for different time periods relative to control fish that were not socially separated. We found that RMR was repeatable in fish in the control group, while the repeatability of RMR disappeared quickly (even within 7 days) when fish were exposed to social separation. This study is the first to our knowledge to examine the role of social separation for different time periods on the repeatability of intra-individual physiological variation in fish. We highlight that the inter-individual repeatability of metabolic rate can be substantial over time but was eliminated by social separation. The findings indicate that the repeatability of metabolic rate in fish is condition dependent, and that the change in repeatability of metabolic rate should not be overlooked when considering the ecological and evolutionary effects of environmental change.


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