|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online June 29, 2007
Journal of Experimental Biology 210, 2444-2452 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.005587
Thermoregulation in pronghorn antelope (Antilocapra americana Ord) in the summer
1 Department of Zoology and Physiology, University of Wyoming, Laramie, WY
82071, USA
2 Department of Physiology, University of the Witwatersrand, Johannesburg,
South Africa
3 Physiology, School of Biomedical and Chemical Sciences, University of
Western Australia, Perth, Australia
* Author for correspondence (e-mail: mitchg{at}uwyo.edu)
Accepted 16 May 2007
We have used thermistor/data logger assemblies to measure temperatures in
the brain, carotid artery, jugular vein and abdominal cavity, and
subcutaneously, in five pronghorn antelope over a summer in Wyoming. Globe and
air temperature varied by up to 
50°C daily during the summer and
maximum solar radiation was 900 W m–2. Brain temperature
(38.9±0.3°C) was consistently 0.2–0.5°C higher than
carotid blood temperature (38.6±0.3°C), which was the same as
abdominal temperature (38.8±0.4°C). Jugular blood temperature
(38.0±0.4°C) varied, probably because of changes in Respiratory
Evaporative Heat Loss (REHL), and was lower than other temperatures.
Subcutaneous temperature (38.3±0.6°C) varied, probably because of
peripheral vasoactivity, but on average was similar to other temperatures.
Carotid blood temperature had a circadian/nycthemeral rhythm weakly but
significantly (r=0.634) linked to the time of sunrise, of amplitude
0.8±0.1°C. There were daily variations of up to 2.3°C in
carotid body temperature in individual animals. An average range of carotid
blood temperature of 3.1±0.4°C over the study period was recorded
for the group, which was significantly wider than the average variation in
brain temperature (2.3±0.6°C). Minimum carotid temperature
(36.4±0.8°C) was significantly lower than minimum brain temperature
(37.7±0.5°C), but maximum brain and carotid temperatures were
similar. Brain temperature was kept relatively constant by a combination of
warming at low carotid temperatures and cooling at high carotid temperatures
and so varied less than carotid temperature. This regulation of brain
temperature may be the origin of the amplitude of the average variation in
carotid temperature found, and may confer a survival advantage.
Key words: pronghorn, brain warming, thermoregulation
Related articles in JEB:
This article has been cited by other articles:
|
|
 |
|
  J. Hebert, A. Lust, A. Fuller, S. K. Maloney, D. Mitchell, and G. Mitchell Thermoregulation in pronghorn antelope (Antilocapra americana, Ord) in winter J. Exp. Biol., March 1, 2008; 211(5): 749 - 756. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Blackburn WARM BRAIN, COLD BODY J. Exp. Biol., July 15, 2007; 210(14): i - i. [Full Text] [PDF]
|
|
