Body temperatures and respiratory rates of free-ranging Merino sheep in and out of shade during summer

1991 ◽  
Vol 42 (8) ◽  
pp. 1347 ◽  
Author(s):  
KG Johnson
Keyword(s):  
Heat Production ◽  
Solar Heating ◽  
Body Temperatures ◽  
Merino Sheep ◽  
Heat Stimulus ◽  
Data Loggers ◽  
Thermal Status ◽  
Sun And Shade ◽  
Free Ranging ◽  
Trunk Skin

Shade use by 20 unrestrained Merino wethers carrying 23-31 mm wool was monitored as they grazed dry pasture during summer (Ta max = 28-41 �C). During 17 24-h periods intra-abdominal (Tb) and trunk-skin (Tsk) temperatures were recorded with ambulatory data-loggers at 1 or 5 minute intervals; in 11 periods respiratory rates were also counted each hour during daylight. The four sheep that used shade least (6% of 8 h day) had mean, maximum and minimum Tb no different to those of the four sheep that used shade most (39%). Maximum and minimum Tb each day occurred 1-2 h earlier in animals inclined to stay in sun rather than shade. Tsk varied in sheep shuttling in and out of shade, but mean mid-back skin temperature was only slightly, and not significantly, higher for animals in sun than shade. Respiratory rates also were similar for animals in sun and shade. The similarity of thermal status of animals in and out of shade was unexpected. This may have arisen because animals had different rates of evaporative cooling that were not reflected in respiratory rates, or possibly different rates of heat production. Alternatively, all animals could have been effectively insulated from solar heating by their wool, though they presumably experienced some heat stimulus since all used shade at some time. Shade may be of benefit

Telemetered body temperatures in a group of cattle during gestation and lactation

1987 ◽  
Vol 108 (3) ◽  
pp. 683-685 ◽  
Author(s):  
I. L. Bennett ◽  
C. R. Holmes
Keyword(s):  
Heat Stress ◽  
Body Temperature ◽  
Dairy Cattle ◽  
Heat Production ◽  
Body Temperatures ◽  
Free Ranging

In tropical and subtropical areas many cattle suffer from heat stress for more than half of each year. Added to the environmental heat stress is the heat production associated with lactation (Berman et al. 1985) and the resultant increased storage of heat (Araki et al. 1984). While the net effect of lactation on body temperature has been evaluated in dairy cattle (Collier et al. 1982) its effect on beef breeds in tropical and subtropical areas has not been defined. This is now possible with improved telemetry equipment, which allows body temperatures of free-ranging cattle to be monitored up to distance of 400 m.

Skin and abdominal temperatures recorded by data loggers attached to Merino sheep voluntarily staying out of shade

1990 ◽  
Vol 41 (4) ◽  
pp. 781 ◽  
Author(s):  
CM Sherwin ◽  
KG Johnson
Keyword(s):  
Mammalian Species ◽  
Dorsal Surface ◽  
Diurnal Rhythms ◽  
The Sun ◽  
Body Temperatures ◽  
Ambient Conditions ◽  
Data Loggers ◽  
Thermal Status ◽  
Using Data ◽  
Skin Temperatures

To investigate individual differences in thermal status of sheep during voluntary shading, a method of recording body temperatures was developed using data loggers attached to free-ranging animals. During summer, recordings were made of body temperatures of Merino wethers grazing irrigated pasture. Despite shade being readily accessible, the sheep voluntarily stayed in the sun throughout the day. Twenty, 24-h records of intra-abdominal temperature and 12 of concurrent skin temperature were obtained. Both core and skin temperatures exhibited diurnal rhythms influenced by ambient conditions. Short-term fluctuations without obvious cause also occurred in both body temperatures. Skin temperatures of the dorsal surface were considerably higher than previously reported. Core temperatures of sheep voluntarily staying in the sun were not hyperthermic. The maximum 24-h range in intra-abdominal temperature (i.e. 1.9�C) does not support previous data (Bligh and Harthoorn 1965) that indicated sheep might be more thermostable than other mammalian species. The effective heat load and thermal displacement were apparently insufficient to cause the sheep to seek shade in competition with other factors influencing their behaviour.

What's hot and what's not: defining torpor in free-ranging birds and mammals

2001 ◽  
Vol 79 (10) ◽  
pp. 1885-1890 ◽  
Author(s):  
Robert MR Barclay ◽  
Cori L Lausen ◽  
Lydia Hollis
Keyword(s):  
Body Temperature ◽  
The Body ◽  
Temperature Sensitive ◽  
The Past ◽  
Data Loggers ◽  
Temperature Thresholds ◽  
Radio Transmitters ◽  
Species Specific ◽  
Free Ranging ◽  
Lowered Body

With the development of small implantable data loggers and externally attached temperature-sensitive radio transmitters, increasing attention is being paid to determining the thermoregulatory strategies of free-ranging birds and mammals. One of the constraints of such studies is that without a direct measure of metabolic rate, it is difficult to determine the significance of lowered body temperatures. We surveyed the literature and found that many different definitions have been used to discriminate torpor from normothermy. Many studies use arbitrary temperature thresholds without regard for the normothermic body temperature of the individuals or species involved. This variation makes comparison among studies difficult and means that ecologically and energetically significant small reductions in body temperature may be overlooked. We suggest that normothermic body temperature for each individual animal should be determined and that torpor be defined as occurring when the body temperature drops below that level. When individuals' active temperatures are not available, a species-specific value should be used. Of greater value, however, are the depth and duration of torpor bouts. We suggest several advantages of this definition over those used in the past.

Effect of cold exposure on various sites of core temperature measurements

1983 ◽  
Vol 54 (4) ◽  
pp. 1025-1031 ◽  
Author(s):  
S. D. Livingstone ◽  
J. Grayson ◽  
J. Frim ◽  
C. L. Allen ◽  
R. E. Limmer
Keyword(s):  
Gastrointestinal Tract ◽  
Metabolic Rate ◽  
Heat Production ◽  
Cold Exposure ◽  
Local Heat ◽  
Control Environment ◽  
Body Temperatures ◽  
Cold Stimulation ◽  
Facial Cooling ◽  
Internal Body

Rectal, esophageal, auditory canal, gastrointestinal tract, and sublingual temperature were recorded on five young Caucasian males who, in an environment of -32 degrees C and 11-km/h wind, sat during one 90-min exposure and walked on a treadmill at 2.9 km/h during another. The clothing permitted cooling of their torsos while giving adequate protection to their extremities. Control exposures involved subjects sitting in still air at 24–26 degrees C dressed only in thermal underwear. In the control environment all of the internal body temperatures measured gave comparable and consistent values; however, cold exposure affected the various sites differently. Esophageal temperatures fluctuated rapidly as a result of subjects swallowing cold saliva. Sublingual temperatures were below the lower limit of a clinical thermometer, possibly because of facial cooling. Auditory canal temperatures were low, perhaps also because of facial cooling. Rectal temperatures were high as were the gastrointestinal tract temperatures, due perhaps to local heat production in response to cold stimulation. Metabolic rate increased initially in the cold and again toward the end of the cold exposure.

Response of Negro and white males to cold

1959 ◽  
Vol 14 (5) ◽  
pp. 798-800 ◽  
Author(s):  
P. F. Iampietro ◽  
R. F. Goldman ◽  
E. R. Buskirk ◽  
David E. Bass
Keyword(s):  
Heat Production ◽  
Cold Injury ◽  
Water Bath ◽  
Whole Body ◽  
Group Differences ◽  
Body Temperatures ◽  
White Males ◽  
Body Cooling ◽  
Whole Body Cooling

Heat production and body temperatures were measured in matched groups of U.S. Negro and white soldiers during whole body cooling and finger temperatures were measured when only the digits were cooled. Whole body cooling was accomplished by having the subjects, clad only in shorts, sit for 2 hours in a chamber at 50℉ with a 5-mph wind. Digital cooling was accomplished by having the subjects immerse the fingers in a water bath at 32℉ for 45 minutes. During whole body cooling there were no group differences with respect to the following: heat production, skin and rectal temperatures. During digital cooling white subjects had higher finger temperatures and the ‘hunting’ reaction was more pronounced than for Negroes. In addition, the white subjects required a shorter period for the onset of the first ‘rewarming’ of the fingers. The implications of these findings with reference to the reported higher incidence of cold injury among Negro soldiers are discussed. Submitted on February 19, 1959

Body Temperatures of Free-Ranging Platypuses, Ornithorhynchus anatinus (Monotremata), with Observations on their Use of Burrows

1983 ◽  
Vol 31 (2) ◽  
pp. 117 ◽  
Author(s):  
TR Grant
Keyword(s):  
Thermal Stresses ◽  
Cold Water ◽  
Body Temperatures ◽  
Ornithorhynchus Anatinus ◽  
The Face ◽  
Free Ranging

Body temperatures (T*h) of free-ranging platypuses were monitored by means of radiotelemetry; although fluctuations of up to 2.8�C occurred in some individuals, most T*b measured were close to 32�C, even during immersion in cold water for up to 12 h. Platypuses spent up to 51% of their day foraging in water, and during such activities 71% of the animals studied used more than one particular burrow. One platypus maintained its T*b, while swimming in water of 0�C in a partly frozen river for at least 5 h. The platypus is a competent homeotherm which maintains a constant T*b in the face of the considerable thermal stresses imposed on it during winter in the southern part of its range.

Relation of changing levels of physical fitness to human cold acclimatization

1961 ◽  
Vol 16 (2) ◽  
pp. 226-230 ◽  
Author(s):  
Earl J. Heberling ◽  
Thomas Adams
Keyword(s):  
Physical Activity ◽  
Cold Exposure ◽  
Physical Training ◽  
Normal Activity ◽  
Body Temperatures ◽  
Cold Acclimatization ◽  
Caucasian Men ◽  
Cold Chamber ◽  
Skin Temperatures ◽  
Trunk Skin

Five nude Caucasian men were exposed for 1 hour to a temperature of 10° α 1°C in a cold chamber after normal activity, after physical training, and after bivouac in the interior of Alaska for 6 weeks during January and February. Body temperatures (hand, foot, trunk, skin, and rectal, recorded during exposure to acute cold, were the criteria by which the effects of the changing levels of physical training and the cold-acclimatizing encampment were compared and judged. After the program of physical training, but before the bivouac, skin and extremity temperatures were statistically higher than those recorded before training; no differences were noted after the bivouac, when the level of physical training remained unchanged and the only variable was exposure to cold. These data confirm an earlier suggestion that commonly accepted indices of acclimatization, (elevated skin temperatures) may also result from chronically elevated levels of physical activity. Additional evidence indicates the limitations of the bivouac or field exercises for 'cold exposure,' and suggests the questionable value of accepting physiological and thermal readjustments that occur during such programs as being indicative of the effects of cold. Submitted on July 5, 1960

Temperature regulation in the tortoise Testudo hermanni, studied with indwelling probes

1996 ◽  
Vol 17 (2) ◽  
pp. 91-102 ◽  
Author(s):  
C. Huot-Daubremont ◽  
D. Bradshaw ◽  
C. Grenot
Keyword(s):  
Temperature Regulation ◽  
Temperature Sensitive ◽  
Behavioural Thermoregulation ◽  
Body Temperatures ◽  
South Eastern ◽  
Testudo Hermanni ◽  
Free Ranging

AbstractBehavioural thermoregulation has been studied in the terrestrial tortoise Testudo hermanni in south-eastern France by implanting temperature-sensitive probes in free-ranging individuals. Three tortoises were monitored over a period of nine months (July to March); they maintained body temperatures close to their preferendum for periods of several hours each day. These results are of interest as doubt has been expressed in the literature on the thermoregulatory capacities of Testudo hermanni in the northernmost part of its range.

Diurnal refuge-site selection by Brown Treesnakes (Boiga irregularis) on Guam

2008 ◽  
Vol 29 (2) ◽  
pp. 284-287 ◽  
Author(s):  
Brad Coupe ◽  
Nancy Anderson ◽  
Thomas Hetherington ◽  
Gad Perry ◽  
Joseph Williams
Keyword(s):  
Site Selection ◽  
Thermal Characteristics ◽  
Boiga Irregularis ◽  
Brown Treesnake ◽  
Data Loggers ◽  
Radio Transmitters ◽  
Natural Range ◽  
Brown Tree Snakes ◽  
Free Ranging ◽  
Arboreal Snakes

Abstract Diurnal refuge-site selection was studied in eleven free-ranging brown tree snakes (Boiga irregularis) in tropical forest on the island of Guam. These nocturnal and mostly arboreal snakes were tracked using implanted radio-transmitters. A vegetation survey of the study site was performed to determine if brown treesnakes non-randomly select certain plants for refuge-sites, and thermal profiles of representative refuge sites were obtained with Hobo data loggers. Brown treesnakes preferentially used Pandanus crowns for refuge-sites. Although Pandanus represents a small proportion (3.6%) of the forest, most snakes used Pandanus most of the time for refuge. The thermal characteristics of Pandanus were comparable to those of other refuge-sites. We speculate that features of Pandanus that provide basking opportunities and moist microhabitats may be important for brown treesnakes. As Pandanus is widely distributed throughout the natural range of the brown treesnake, this genus may represent an important refuge-site for this species.

Changing physiological relationships in men under acute cold stress

1970 ◽  
Vol 48 (1) ◽  
pp. 1-10 ◽  
Author(s):  
James F. O'Hanlon Jr. ◽  
Steven M. Horvath
Keyword(s):  
Rectal Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Heat Content ◽  
Body Temperatures ◽  
Older Subjects ◽  
Skin Temperatures ◽  
Different Levels ◽  
Body Heat ◽  
Thigh Temperature

Thirty-four men were exposed to 8 °C for 2 h. Their reactions were studied to indicate how physiological relationships change during exposure to cold. Measurements of various body temperatures, MST, MBT, body heat content (BHC), [Formula: see text], heat production, and heart rate (HR) were made before the onset of and periodically during cold exposure. Various skin temperatures fell to different levels while rectal temperature rose slightly, then fell 0.3 °C by the end of the exposure. BHC declined by 6%, [Formula: see text] nearly doubled, [Formula: see text] and heat production increased by 66 and 75% respectively, and HR changed little during cold exposure. Relationships which changed most significantly during cold exposure were those between MST and rectal temperature, certain skin temperatures and rectal temperature, [Formula: see text] (also heat production) and BHC, [Formula: see text] and rectal temperature, and finally, those between every body temperature and the age of the subjects. Relationships which also changed were those between finger and toe temperature as well as those between [Formula: see text] (also heat production) and each of the following: [Formula: see text], rectal temperature, thigh temperature, HR, and age. These results indicated that (1) temperature in the upper extremities was actively maintained at a higher level than temperature in the lower extremities, (2) increased metabolism became a progressively more effective adaptation than redistribution of blood volume, (3) subjects with the lowest BHC tended to increase their metabolism the most, (4) [Formula: see text] was inversely related to core temperature after the latter fell below normal, (5) HR was unrelated to the increase in [Formula: see text], (6) the usual inverse relationship between age and metabolism was not found in the cold, and finally, (7) older subjects generally tended to maintain higher body temperatures than younger subjects.

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