October 28, 2011
Reindeer Pant To Release Heat
Researchers have discovered that reindeer have multiple methods of keeping cool through their thick, long coats.
Their thick coats are the perfect protection in keeping the cold away from their bodies in the Arctic winters that they endure. But the researchers wondered how they keep cool when they are active and generating heat Arnoldus Blix, one of the authors of the study from the University of TromsÃ¸, Norway, says that these animals have three tactics for staying cool.
The first cooling technique the reindeer use is panting with their mouths closed to evaporate water from the nose. Secondly they pant with their mouths open to evaporate water from the tongue. Finally when their body temperature finally rises to more dangerous levels, around 39 degrees C, they pant with their mouths open and activate an internal cooling system that diverts cooler blood from the front of the face directly to the brain.
The reindeer were chosen for the study because of their domesticated nature. According to Blix, “Reindeer are the best animals to work with; once they trust the trainer they will do anything for you.”
The researchers trained the reindeer to run on a treadmill at 9 km/h in temperatures that ranged from 10 degrees C up to 30 degrees C. In the beginning of the run the reindeer had a breath rate of 7 breaths per minute and then the rate increased up to 260 breaths per minute. The high rate of breathing was so the inhaled chilly air and evaporated water from mucous membranes cooled the blood in the nasal sinuses before sending it back into the body through the jugular vein to keep their temperature down, according to Blix.
Study findings were published in the Journal of Experimental Biology.
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