Thermoregulation and ventilation in the tawny frogmouth, Podargus strigoides: a low-metabolic avian species

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.

1973 ◽  
Vol 51 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Robert A. MacArthur ◽  
Lawrence C. H. Wang

The mean body temperature of pika measured by radiotelemetry under field and laboratory conditions was 40.1 °C (range = 37.9–42.7) over an ambient temperature range of −9.3 to 24 °C. The maximum daily fluctuation in any one individual was less than 2.6 °C and no seasonal difference in the level of body temperature maintained was observed. Hyperthermia and death occurred after a 2-h exposure to ambient temperatures higher than 28 °C, inclusive.The basal metabolic rate was 1.53 cc O2/g h and the thermal conductance was between 0.096 and 0.050 cc O2/gh °C, 143% and 101–53%, respectively, of their predicted weight-specific values. The relatively high body temperature of pika is attributed to its high basal metabolic rate and good insulation. The low thermal conductance, which indicates a reduction of energy consumption at ambient temperatures below the lower critical temperature (21 °C), favors the overwinter survival of this species when only limited food storage is available.


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 54 (1) ◽  
pp. 9 ◽  
Author(s):  
Alexander N. Larcombe ◽  
Philip C. Withers ◽  
Stewart C. Nicol

Thermoregulatory, metabolic and ventilatory parameters measured for the Tasmanian eastern barred bandicoot (Perameles gunnii) in thermoneutrality (ambient temperature = 30°C) were: body temperature 35.1°C, basal metabolic rate 0.55 mL O2 g–1 h–1, wet thermal conductance 2.2 mL O2 g–1 h–1 °C–1, dry thermal conductance 1.4 J g–1 h–1 °C–1, ventilatory frequency 24.8 breaths min–1, tidal volume 9.9 mL, minute volume of 246 mL min–1, and oxygen extraction efficiency 22.2%. These physiological characteristics are consistent with a cool/wet distribution, e.g. high basal metabolic rate (3.33 mL O2 g–0.75 h–1) for thermogenesis, low thermal conductance (0.92 J g–1 h–1 °C–1 at 10°C) for heat retention and intolerance of high ambient temperatures (≥35°C) with panting, hyperthermia and high total evaporative water loss (16.9 mg H2O g–1 h–1).


1973 ◽  
Vol 51 (8) ◽  
pp. 841-846 ◽  
Author(s):  
Lawrence C. H. Wang ◽  
Douglas L. Jones ◽  
Robert A. MacArthur ◽  
William A. Fuller

Unlike other lagomorphs or any other mammals living in a cold environment, the basal metabolic rate of the arctic hare, Lepus arcticus monstrabilis (0.36 cm3 O2/g per hour) was only 62–83% of the values predicted from its body weight. The minimum thermal conductance (0.010 cm3 O2/g per hour per degree centigrade) was also reduced to only 51–59% of its weight-specific value (0.019–0.017 cm3 O2/g per hour per degree centigrade). The normal body temperature (38.9C), however, was comparable to that of other lagomorphs. The daily energy consumption between ambient temperatures of −24 and 12.5C was between 262 and 133 kcal, which is 6–43% above the minimum resting values at corresponding ambient temperatures.It is concluded that the reduction of surface area to volume ratio and the effectiveness of its insulation are sufficient compensations so that the arctic hare can maintain a normal body temperature with a depressed basal metabolic rate. Such a reduction of metabolism is energetically adaptive for a species living exclusively in a cold and relatively barren habitat.


1965 ◽  
Vol 20 (3) ◽  
pp. 405-410 ◽  
Author(s):  
Hermann Pohl

Characteristics of cold acclimation in the golden hamster, Mesocricetus auratus, were 1) higher metabolic rate at -30 C, 2) less shivering when related to ambient temperature or oxygen consumption, and 3) higher differences in body temperature between cardiac area and thoracic subcutaneous tissues at all ambient temperatures tested, indicating changes in tissue insulation. Cold-acclimated hamsters also showed a rise in temperature of the cardiac area when ambient temperature was below 15 C. Changes in heat distribution in cold-acclimated hamsters suggest higher blood flow and heat production in the thoracic part of the body in the cold. The thermal conductance through the thoracic and lumbar muscle areas, however, did not change notably with lowering ambient temperature. Marked differences in thermoregulatory response to cold after cold acclimation were found between two species, the golden hamster and the thirteen-lined ground squirrel, showing greater ability to regulate body temperature in the cold in hamsters. hibernator; oxygen consumption— heat production; body temperature — heat conductance; muscular activity — shivering; thermoregulation Submitted on July 6, 1964


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.


1992 ◽  
Vol 40 (5) ◽  
pp. 523 ◽  
Author(s):  
PC Withers

The Barrow I. golden bandicoot (Isoodon auratus) is a small arid-adapted marsupial. It has a low and labile body temperature, a low basal metabolic rate, a low thermal conductance, and a low rate of evaporative water loss. Its metabolic, thermal and hygric physiology resembles that of another arid-adapted bandicoot, the bilby, and differs from temperate and tropical bandicoots.


2003 ◽  
Vol 51 (1) ◽  
pp. 43 ◽  
Author(s):  
K. J. Dixon ◽  
R. W. Rose

The energetics of the lesser long-eared bat, Nyctophilus geoffroyi, at the southern limits of its distribution was examined to determine whether this species shows any latitudinal variation in this aspect of its physiological ecology. Estimates of metabolic rate were obtained from the oxygen consumption of adult bats in a non-reproductive condition. Values for the thermoneutral zone were similar but thermal conductance was lower than for bats from mainland of Australia. Euthermic body temperature was higher (37.4 ± 0.2°C) and the ambient temperature at which N. geoffroyi entered torpor has a downward shift of 10°C at the southern limits of its distribution. The basal metabolic rate (1.12 ± 0.14 mL O2 g–1 h–1) also was lower than in lower latitudes. Thermal conductance of the bats in Tasmania was lower than that found in New South Wales or Western Australia (0.29 v. 0.38–0.39 mL O2 g–1 h–1 °C–1). All of these differences are apparently adaptations to a cooler environment.


1942 ◽  
Vol 19 (2) ◽  
pp. 124-132
Author(s):  
D. L. GUNN ◽  
C. A. COSWAY

1. The carpet type of Barcroft respiration apparatus previously used by Gunn for cockroaches gives results comparable with those now obtained with a new basket type. 2. Desiccated cockroaches use oxygen at the same rate per animal as undesiccated specimens. If, however, the rates are calculated with reference to the weight of the animal at the time of the experiment, since the desiccated animals tested had lost about 25% of their original weight, their rates of oxygen consumption appeared to have gone up. 3. Both normal and desiccated animals used oxygen slightly faster in moist air than in dry. Part of this increase must be attributed to a higher body temperature in moist air at 25° C. than in drier air at 25° C. Part of it may be due to greater activity in moist air than in dry, slight though the activity was in both cases. 4. There is no reason to believe that, at a given body temperature, air humidity influences basal metabolic rate.


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.


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