Hibernation and Daily Torpor in Marsupials - a Review

1994 ◽  
Vol 42 (1) ◽  
pp. 1 ◽  
Author(s):  
F Geiser
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Daily Torpor ◽  
Metabolic Rates ◽  
Torpor Bouts

Most heterothermic marsupials appear to display one of the two patterns of torpor that have been described in placental mammals. During shallow, daily torpor body temperature (T(b)) falls for several hours from about 35-degrees-C to values between 11 and 28-degrees-C, depending on the species, and metabolic rates fall to about 10-60% of the basal metabolic rate (BMR). In contrast during deep and prolonged torpor (hibernation), T(b) falls to about 1-5-degrees-C, metabolic rates to about 2-6% of BMR and torpor bouts last for 5-23 days. Shallow, daily torpor has been observed in the opossums (Didelphidae), the carnivorous marsupials (Dasyuridae) and the small possums (Petauridae). Daily torpor may also occur in the numbat (Myrmecobiidae) and the marsupial mole (Notoryctidae). Deep and prolonged torpor (hibernation) has been observed in the pygmy possums (Burramyidae), feathertail glider (Acrobatidae) and Dromiciops australis (Microbiotheriidae). The patterns of torpor in marsupials are paralleled by those of monotremes, placentals and even birds. These similarities in torpor patterns provide some support to the hypothesis that torpor may be plesiomorphic. However, as endothermy and torpor in birds apparently has evolved separately from that in mammals and as torpor occurrence in mammals can change within only a few generations it appears more likely that torpor in endotherms is convergent.

Hibernation in the Eastern Pygmy Possum, Cercartetus-Nanus (Marsupialia, Burramyidae)

1993 ◽  
Vol 41 (1) ◽  
pp. 67 ◽  
Author(s):  
F Geiser
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Air Temperature ◽  
The Body ◽  
Daily Torpor ◽  
Rate Of Oxygen Consumption ◽  
The Mean ◽  
Cercartetus Nanus ◽  
Torpor Bouts

The pattern of torpor was examined in the eastern pygmy possum, Cercartetus nanus (21 g). Animals displayed torpor regularly in the laboratory, and the occurrence of torpor increased with decreasing air temperature (T(a)). At high T(a) (18-degrees-C) animals usually exhibited daily torpor, but torpor bouts of up to 2 days were observed occasionally. The duration of torpor bouts lengthened with a lowering of T(a) and the mean bout duration at T(a) = 5-degrees-C was 17.0 +/- 2.5 days. The minimum metabolic rate (measured as rate of oxygen consumption) of torpid individuals was 0.018 +/- 0.003 mL O2 g-1 h-1, which is less than 2% of the basal metabolic rate. The body temperature (T(b)) Of torpid animals fell to a minimum of 1.3 +/- 0.4-degrees-C. These results clearly demonstrate that Cercartetus nanus is a deep hibernator.

scholarly journals Physiological Responses to Temperature by Whip-Poor-Wills: More Evidence for the Evolution of Low Metabolic Rates in Caprimulgiformes

The Condor ◽  
2004 ◽  
Vol 106 (4) ◽  
pp. 921-925
Author(s):  
Jeffrey E. Lane ◽  
David L. Swanson ◽  
R. Mark Brigham ◽  
Andrew E. McKechnie
Keyword(s):  
Metabolic Rate ◽  
Ambient Temperature ◽  
South Dakota ◽  
Basal Metabolic Rate ◽  
Ecological Niche ◽  
Physiological Responses ◽  
Metabolic Responses ◽  
Phylogenetic Position ◽  
Daily Torpor ◽  
Metabolic Rates

Abstract We measured the metabolic responses of nine Whip-poor-wills (Caprimulgus vociferus), captured in southeast South Dakota, to incremental changes in ambient temperature within the range of 0–40°C. Similar to other members of the Caprimulgiformes, Whip-poor-wills exhibited a basal metabolic rate that was lower than predicted by allometry. We compared basal metabolic rates of six caprimulgiform species (our data plus published values for five other species) with those of 82 other avian species using both conventional and phylogenetically independent ANCOVAs. The low basal metabolic rate of Caprimulgiformes was not explained by phylogenetic position. A low basal metabolic rate, together with the widespread ability of birds in this order to use daily torpor, seemingly has enabled members of this group to occupy their unique ecological niche (crepuscular insectivory). Respuestas Fisiológicas de Caprimulgus vociferus a la Temperatura: Más Evidencia a Favor de la Evolución de una Baja Tasa Metabólica en Caprimúlgidos Resumen. Medimos las respuestas metabólicas a aumentos de la temperatura ambiental en un rango de 0–40°C en nueve individuos de Caprimulgus vociferus capturados en Dakota del Sur. De manera similar a otros Caprimúlgidos, C. vociferus presentó una tasa metabólica basal menor a la predicha por parámetros alométricos. Comparamos las tasas metabólicas basales de seis especies de caprimúlgidos (nuestros datos más datos publicados para otras cinco especies) con aquellas de otras 82 especies de aves utilizando aná lisis de co-varianza (ANCOVA) convencionales y filogenéticamente independientes. La baja tasa metabó lica basal de los caprimúlgidos no fue explicada por su posición filogenética. La baja tasa metabólica basal, junto a la capacidad generalizada de las aves de este orden de usar torpor diario, aparentemente han permitido a los miembros de este grupo a ocupar un nicho ecológico único (insectivoría crepuscular).

scholarly journals The decoupled nature of basal metabolic rate and body temperature in endotherm evolution

Nature ◽  
2019 ◽  
Vol 572 (7771) ◽  
pp. 651-654 ◽  
Author(s):  
Jorge Avaria-Llautureo ◽  
Cristián E. Hernández ◽  
Enrique Rodríguez-Serrano ◽  
Chris Venditti
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Basal Metabolic Rate

The relationship between body mass and rate of rewarming from hibernation and daily torpor in mammals

1990 ◽  
Vol 151 (1) ◽  
pp. 349-359 ◽  
Author(s):  
F. Geiser ◽  
R. V. Baudinette
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Air Temperature ◽  
Basal Metabolic Rate ◽  
Strong Relationship ◽  
The Other ◽  
Daily Torpor ◽  
Pronounced Increase ◽  
The Relationship

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.

Changes in body temperature and basal metabolic rate of the ama

1963 ◽  
Vol 18 (3) ◽  
pp. 483-488 ◽  
Author(s):  
B. S. Kang ◽  
S. H. Song ◽  
C. S. Suh ◽  
S. K. Hong
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Water Temperature ◽  
Basal Metabolic Rate ◽  
Cold Water ◽  
Four Seasons ◽  
Before And After ◽  
Average Skin ◽  
Skin Temperatures ◽  
Average Body

Oral temperatures of Korean diving women (ama) were measured before and after diving work in four seasons of the year. Their basal metabolic rate, measured in four seasons, was compared to that of nondiving women who lived in the same community and ate the same diet as the ama. Average oral temperatures declined to 35 C after 70 min of work in summer (water temp., 27 C) and to 33 C after 15 min of work in the winter (water temp., 10 C). Average body temperature, computed from weighted oral and average skin temperatures, declined to 34.6 C in summer and to 30 C in winter. Duration of work periods was determined principally by water temperature, since oral temperature declined at a rate inversely proportional to water temperature. The lower deep body temperatures which the ama endure in winter do, however, prolong their winter work period. The BMR of nondiving women was the same as the Dubois standard throughout the year. However, the BMR of ama varied with the season, ranging from +5 of the Dubois standard in summer to +35 in winter. We conclude that the elevated BMR of ama during the winter is cold adaptation, induced by repeated immersion in cold water. Submitted on November 23, 1962

scholarly journals Circulation and metabolic rates in a natural hibernator: an integrative physiological model

2010 ◽  
Vol 299 (6) ◽  
pp. R1478-R1488 ◽  
Author(s):  
Marshall Hampton ◽  
Bethany T. Nelson ◽  
Matthew T. Andrews
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Core Body Temperature ◽  
Circulatory System ◽  
Physiological Model ◽  
Ground Squirrels ◽  
Metabolic Rates ◽  
Spermophilus Tridecemlineatus ◽  
Brown Adipose ◽  
Core Body

Small hibernating mammals show regular oscillations in their heart rate and body temperature throughout the winter. Long periods of torpor are abruptly interrupted by arousals with heart rates that rapidly increase from 5 beats/min to over 400 beats/min and body temperatures that increase by ∼30°C only to drop back into the hypothermic torpid state within hours. Surgically implanted transmitters were used to obtain high-resolution electrocardiogram and body temperature data from hibernating thirteen-lined ground squirrels ( Spermophilus tridecemlineatus ). These data were used to construct a model of the circulatory system to gain greater understanding of these rapid and extreme changes in physiology. Our model provides estimates of metabolic rates during the torpor-arousal cycles in different model compartments that would be difficult to measure directly. In the compartment that models the more metabolically active tissues and organs (heart, brain, liver, and brown adipose tissue) the peak metabolic rate occurs at a core body temperature of 19°C approximately midway through an arousal. The peak metabolic rate of the active tissues is nine times the normothermic rate after the arousal is complete. For the overall metabolic rate in all tissues, the peak-to-resting ratio is five. This value is high for a rodent, which provides evidence for the hypothesis that the arousal from torpor is limited by the capabilities of the cardiovascular system.

Standard metabolic rate and preferred body temperatures in some Australian pythons

1998 ◽  
Vol 46 (4) ◽  
pp. 317 ◽  
Author(s):  
Gavin S. Bedford ◽  
Keith A. Christian
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Thermal Sensitivity ◽  
Standard Metabolic Rate ◽  
Allometric Equations ◽  
Metabolic Rates ◽  
Body Temperatures ◽  
Daily Cycle ◽  
Preferred Body Temperature

Pythons have standard metabolic rates and preferred body temperatures that are lower than those of most other reptiles. This study investigated metabolic rates and preferred body temperatures of seven taxa of Australian pythons. We found that Australian pythons have particularly low metabolic rates when compared with other boid snakes, and that the metabolic rates of the pythons did not change either seasonally or on a daily cycle. Preferred body temperatures do vary seasonally in some species but not in others. Across all species and seasons, the preferred body temperature range was only 4.9˚C. The thermal sensitivity (Q10) of oxygen consumption by pythons conformed to the established range of between 2 and 3. Allometric equations for the pooled python data at each of the experimental temperatures gave an equation exponent of 0.72–0.76, which is similar to previously reported values. By having low preferred body temperatures and low metabolic rates, pythons appear to be able to conserve energy while still maintaining a vigilant ‘sit and wait’ predatory existence. These physiological attributes would allow pythons to maximise the time they can spend ‘sitting and waiting’ in the pursuit of prey.

scholarly journals Heart rate reveals torpor at high body temperatures in lowland tropical free-tailed bats

2017 ◽  
Vol 4 (12) ◽  
pp. 171359 ◽  
Author(s):  
M. Teague O'Mara ◽  
Sebastian Rikker ◽  
Martin Wikelski ◽  
Andries Ter Maat ◽  
Henry S. Pollock ◽  
...  
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Ambient Temperature ◽  
The Body ◽  
Metabolic Rates ◽  
Body Temperatures ◽  
Wide Range ◽  
Save Energy ◽  
Molossus Molossus

Reduction in metabolic rate and body temperature is a common strategy for small endotherms to save energy. The daily reduction in metabolic rate and heterothermy, or torpor, is particularly pronounced in regions with a large variation in daily ambient temperature. This applies most strongly in temperate bat species (order Chiroptera), but it is less clear how tropical bats save energy if ambient temperatures remain high. However, many subtropical and tropical species use some daily heterothermy on cool days. We recorded the heart rate and the body temperature of free-ranging Pallas' mastiff bats ( Molossus molossus ) in Gamboa, Panamá, and showed that these individuals have low field metabolic rates across a wide range of body temperatures that conform to high ambient temperature. Importantly, low metabolic rates in controlled respirometry trials were best predicted by heart rate, and not body temperature . Molossus molossus enter torpor-like states characterized by low metabolic rate and heart rates at body temperatures of 32°C, and thermoconform across a range of temperatures. Flexible metabolic strategies may be far more common in tropical endotherms than currently known.

scholarly journals Brain size varies with temperature in vertebrates

2014 ◽  
Author(s):  
James F Gillooly
Keyword(s):  
Body Size ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Temperature Dependence ◽  
Aerobic Capacity ◽  
Brain Size ◽  
Metabolic Rates ◽  
Temperature Dependent ◽  
Spatial And Temporal Scales ◽  
Effects Of Temperature

The tremendous variation in brain size among vertebrates has long been thought to be related to differences in species’ metabolic rates. Species with higher metabolic rates can supply more energy to support the relatively high cost of brain tissue. And yet, while body temperature is known to be a major determinant of metabolic rate, the possible effects of temperature on brain size have scarcely been explored. Thus, here I explore the effects of temperature on brain size among diverse vertebrates (fishes,amphibians, reptiles, birds and mammals). I find that, after controlling for body size,brain size increases exponentially with temperature in much the same way asmetabolic rate. These results suggest that temperature-dependent changes in aerobic capacity, which have long been known to affect physical performance, similarly affect brain size. The observed temperature-dependence of brain size may explain observed gradients in brain size among both ectotherms and endotherms across broad spatial and temporal scales.

Changes in Body Temperature and Basal Metabolic Rate of the Ama☆

2003 ◽  
Vol 14 (3) ◽  
pp. 193-193 ◽  
Author(s):  
Bok Soon Kang ◽  
Seh Hoon Song ◽  
Chung Sam Suh ◽  
Suh Ki Hong
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Basal Metabolic Rate
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