Thermal energetics of female big brown bats (Eptesicus fuscus)

2005 ◽  
Vol 83 (6) ◽  
pp. 871-879 ◽  
Author(s):  
Craig K.R Willis ◽  
Jeffrey E Lane ◽  
Eric T Liknes ◽  
David L Swanson ◽  
R Mark Brigham

We investigated thermoregulation and energetics in female big brown bats, Eptesicus fuscus (Beauvois, 1796). We exposed bats to a range of ambient temperatures (Ta) and used open-flow respirometry to record their metabolic responses. The bats were typically thermoconforming and almost always entered torpor at Tas below the lower critical temperature Tlc of 26.7 °C. Basal metabolic rate (BMR, 16.98 ± 2.04 mL O2·h–1, mean body mass = 15.0 ± 1.4 g) and torpid metabolic rate (TMR, 0.460 ± 0.207 mL O2·h–1, mean body mass = 14.7 ± 1.3 g) were similar to values reported for other vespertilionid bats of similar size and similar to a value for E. fuscus BMR calculated from data in a previous paper. However, we found that big brown bats had a lower Tlc and lower thermal conductance at low Ta relative to those measured in the previous study. During torpor, the minimum individual body temperature (Tb) that we recorded was 1.1 °C and the bats began defending minimum Tb at Ta of approximately 0 °C. BMR of big brown bats was 76% of that predicted for bats based on the relationship between BMR and body mass. However, the Vespert ilionidae have been under-represented in previous analyses of the relationship between BMR and body mass in bats. Our data, combined with data for other vespertilionids, suggest that the family may be characterized by a lower BMR than that predicted based on data from other groups of bats.

1999 ◽  
Vol 47 (2) ◽  
pp. 169 ◽  
Author(s):  
Elke Schleucher

Ptilinopus superbus (body mass 120.4 5.2 g) is a highly specialised, migratory avian frugivore that is widespread in the rainforests of the Indo-Pacific Region and north-eastern Australia. The effect of the specialised diet on metabolic rate (MR) and body temperature (Tb) were investigated at ambient temperatures (Ta) of 13-30ºC in activity (α) and rest (ρ) phases. At thermoneutrality (Ta = 26ºC), the basal metabolic rate (BMR) was 23.2 4.49 J g-1 h-1 , which corresponds closely to the predicted value (22.6 J g-1 h-1). Wet thermal conductance (Cwet) was 2.39 0.45 J g-1 h-1 ºC-1 in α and 1.75 0.13 J g-1 h-1 ºC-1 in ρ for Ta between 13 and 21ºC. These conductances are higher than expected (α: 1.87 J g-1 h-1 ºC-1; ρ: 1.16 J g-1 h-1 ºC-1) for a non-passerine bird of this body mass (M), indicating poor insulation of this tropical species. Tb was 39.6 0.76ºC in α and 38.1 0.55ºC in ρ in the observed Ta range, corresponding closely to expected values (40.9 1.35 in α and 38.6 0.66 in ρ). This study shows no evidence of an influence of the fruit diet on the metabolic physiology of superb fruit doves. Analysis of BMR data for all pigeon species sampled so far provides no evidence that a low basal metabolic rate is a general characteristic of the Columbidae.


1999 ◽  
Vol 47 (2) ◽  
pp. 143 ◽  
Author(s):  
Claus Bech ◽  
Stewart C. Nicol

Oxygen consumption (VO2) and body temperature (Tb) were measured during daytime (corresponding to the normal resting phase) in the tawny frogmouth (Podargus strigoides, mean body mass of 341 g) at ambient temperatures (Ta) between -1ºC and 30ºC. Mean body temperature (over this range of Ta) was 37.8ºC and there was only a small (0.4ºC), and insignificant, day-night variation in Tb. Mean VO2 within thermoneutrality (25-30ºC) was 0.59 mL O2 g-1 h-1 , corresponding to a basal metabolic rate (BMR) of 3.32 W kg-1 . This value is only 61% of the predicted value for a non-passeriform bird. The minimal thermal conductance attained at Ta below thermoneutrality was 0.156 W kg-1 ºC-1, a value which is very close to the allometrically predicted value. The relatively low VO2 was paralleled by a low total ventilatory volume. This, in turn, was mainly the result of a low respiratory frequency (10.2 breaths min-1, only 52% of that expected for a similar-sized bird) whereas tidal volume (6.6 mL [BTPS]) was 107% of the expected value. Thus, our results suggest that the changing ventilatory needs during the evolution of the low VO2 in the tawny frogmouth have been met primarily by changes in respiratory frequency.


2013 ◽  
Vol 82 (5) ◽  
pp. 1009-1020 ◽  
Author(s):  
Lawrence N. Hudson ◽  
Nick J. B. Isaac ◽  
Daniel C. Reuman

1990 ◽  
Vol 151 (1) ◽  
pp. 349-359 ◽  
Author(s):  
F. Geiser ◽  
R. V. Baudinette

1. Rewarming rate from torpor and body mass were inversely related in 86 mammals ranging in body mass between 2 and 8500 g. 2. Most of the mammalian taxa investigated showed a similar change of rewarming rate with body mass. Only the insectivores showed a more pronounced increase in rewarming with a decrease in body mass than did the other taxa. The rates of rewarming of marsupials were similar to those of placentals. 3. At low air temperature (Ta), the rate of rewarming of marsupials was not related to body mass, although a strong relationship between the two variables was observed in the same species at high Ta. 4. The slopes relating rewarming rates and body mass of the mammalian groups and taxa analysed here were similar to those obtained earlier for mass-specific basal metabolic rate (BMR) and body mass in mammals, suggesting that the rate of rewarming and BMR are physiologically linked.


1976 ◽  
Vol 231 (3) ◽  
pp. 903-912 ◽  
Author(s):  
B Pinshow ◽  
MA Fedak ◽  
DR Battles ◽  
K Schmidt-Nielsen

During the antarctic winter emperor penguins (Aptenodytes forsteri) spend up to four mo fasting while they breed at rookeries 80 km or more from the sea, huddling close together in the cold. This breeding cycle makes exceptional demands on their energy reserves, and we therefore studied their thermoregulation and locomotion. Rates of metabolism were measured in five birds (mean body mass, 23.37 kg) at ambient temperatures ranging from 25 to -47 degrees C. Between 20 and -10 degrees C the metabolic rate (standard metabolic rate (SMR)) remained neraly constant, about 42.9 W. Below -10 degrees C metabolic rate increased lineraly with decreasing ambient temperature and at -47 degrees C it was 70% above the SMR. Mean thermal conductance below -10 degrees C was 1.57 W m-2 degrees C-1. Metabolic rate during treadmill walking increased linearly with increasing speed. Our data suggest that walking 200 km (from the sea to the rookery and back) requires less than 15% of the energy reserves of a breeding male emperor penguin initially weighing 35 kg. The high energy requirement for thermoregulation (about 85%) would, in the absence of huddling, probably exceed the total energy reserves.


2003 ◽  
Vol 51 (6) ◽  
pp. 603 ◽  
Author(s):  
M. P. Ikonomopoulou ◽  
R. W. Rose

We investigated the metabolic rate, thermoneutral zone and thermal conductance of the eastern barred bandicoot in Tasmania. Five adult eastern barred bandicoots (two males, three non-reproductive females) were tested at temperatures of 3, 10, 15, 20, 25, 30, 35 and 40°C. The thermoneutral zone was calculated from oxygen consumption and body temperature, measured during the daytime: their normal resting phase. It was found that the thermoneutral zone lies between 25°C and 30°C, with a minimum metabolic rate of 0.51 mL g–1 h–1 and body temperature of 35.8°C. At cooler ambient temperatures (3–20°C) the body temperature decreased to approximately 34.0°C while the metabolic rate increased from 0.7 to 1.3 mL g–1�h–1. At high temperatures (35°C and 40°C) both body temperature (36.9–38.7°C) and metabolic rate (1.0–1.5 mL g–1 h–1) rose. Thermal conductance was low below an ambient temperature of 30°C but increased significantly at higher temperatures. The low thermal conductance (due, in part, to good insulation, a reduced body temperature at lower ambient temperatures, combined with a relatively high metabolic rate) suggests that this species is well adapted to cooler environments but it could not thermoregulate easily at temperatures above 30°C.


2006 ◽  
Vol 274 (1607) ◽  
pp. 287-293 ◽  
Author(s):  
Craig R White ◽  
Tim M Blackburn ◽  
Graham R Martin ◽  
Patrick J Butler

A classic example of ecophysiological adaptation is the observation that animals from hot arid environments have lower basal metabolic rates (BMRs, ml O 2  min −1 ) than those from non-arid (luxuriant) ones. However, the term ‘arid’ conceals within it a multitude of characteristics including extreme ambient temperatures ( T a , °C) and low annual net primary productivities (NPPs, g C m −2 ), both of which have been shown to correlate with BMR. To assess the relationship between environmental characteristics and metabolic rate in birds, we collated BMR measurements for 92 populations representing 90 wild-caught species and examined the relationships between BMR and NPP, T a , annual temperature range ( T r ), precipitation and intra-annual coefficient of variation of precipitation ( P CV ). Using conventional non-phylogenetic and phylogenetic generalized least-squares approaches, we found no support for a relationship between BMR and NPP, despite including species captured throughout the world in environments spanning a 35-fold range in NPP. Instead, BMR was negatively associated with T a and T r , and positively associated with P CV .


Medicina ◽  
2019 ◽  
Vol 55 (8) ◽  
pp. 487
Author(s):  
Joanna Baran ◽  
Aneta Weres ◽  
Ewelina Czenczek-Lewandowska ◽  
Justyna Leszczak ◽  
Katarzyna Kalandyk-Osinko ◽  
...  

Background and Objectives. The purpose of the study was to investigate the relationship between children’s birth weight/length and a risk of overweight and obesity. Materials and Methods. The study involved 747 children from kindergartens, as well as primary and middle schools from southeastern Poland. All the subjects were examined on fasting status. Each child was examined for body mass and height, in order to calculate their body mass index (BMI), and BMI centile. The parents completed a questionnaire related to basic information about the child and the family. Results. In the study group, the male infants presented greater birth body weight and birth body length. A comparison of the distribution of birth weights and lengths between the children with normal BMI and with high BMI showed statistically significant differences only in the case of birth length of 12–15-year-old children and in the group of boys aged 12–15 years. In the case of the female children and the group of 7–11-year-olds a statistically significant difference was found in the BMI centile at a later age—a higher centile was found in the girls and in the children aged 7–11 years classified as adequate for gestational age (AGA). Conclusions. Birth body weight is positively related to BMI centile; however, no significant differences were found in birth weight between children with overweight/obesity and children with normal body weight. Birth length is associated with a lower BMI centile only in boys aged 12–15 years, and lower birth length is found in boys with overweight and obesity.


2020 ◽  
Vol 375 (1793) ◽  
pp. 20190146 ◽  
Author(s):  
Jacob D. Gardner ◽  
Michel Laurin ◽  
Chris L. Organ

Genome size has long been hypothesized to affect the metabolic rate in various groups of animals. The mechanism behind this proposed association is the nucleotypic effect, in which large nucleus and cell sizes influence cellular metabolism through surface area-to-volume ratios. Here, we provide a review of the recent literature on the relationship between genome size and metabolic rate. We also conduct an analysis using phylogenetic comparative methods and a large sample of extant vertebrates. We find no evidence that the effect of genome size improves upon models in explaining metabolic rate variation. Not surprisingly, our results show a strong positive relationship between metabolic rate and body mass, as well as a substantial difference in metabolic rate between endothermic and ectothermic vertebrates, controlling for body mass. The presence of endothermy can also explain elevated rate shifts in metabolic rate whereas genome size cannot. We further find no evidence for a punctuated model of evolution for metabolic rate. Our results do not rule out the possibility that genome size affects cellular physiology in some tissues, but they are consistent with previous research suggesting little support for a direct functional connection between genome size and basal metabolic rate in extant vertebrates. This article is part of the theme issue ‘Vertebrate palaeophysiology’.


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