Biologists have discovered the secret of cold hardiness geese
Birds in winter, lower your heart rate and metabolism
Geese can safely spend the winter in the Northern countries and do not fly far to the South because of its ability to slow down the heart rate and metabolism, and reduce body temperature in the coldest times of the year. To such conclusion Claudia vasher and her colleagues from the University of Vienna, reports Popular mechanics citing Scientific Reports.
“Many animals do not hibernate, such as red deer or Alpine ibex, slow down metabolism and reduce body temperature in order to survive the lack of heat and food during the winter. Our study shows that some birds, such as grey geese, are using similar strategies of survival,” said vasher.
Birds, like mammals, are warm-blooded creatures — they maintain a constant body temperature, burning off the nutrients that allows them to remain active and survive even at low temperatures. This “superpower” has restrictions — when air temperature becomes very low, the organism of the birds can not compensate for heat loss, these birds have to migrate South.
Such problems, as shown by observing the lives of some mammals and birds, sometimes do not prevent animals or not they go into hibernation at all, or use fundamentally different survival strategies. For example, Northern geese usually migrate for short distances from the breeding sites, flying in those regions of Russia, Canada and Northern Europe, where average winter temperatures reach about 5 degrees of a frost.
Vasher and her colleagues tried to uncover the secrets of the survival of these birds, watching a large flock of two hundred of the usual gray geese, living in the kennel of the University near the town of Grünau in the Central part of Austria. Scientists caught a few dozen birds and attached to their body special sensors that collected data on their body temperature, heart rate and other physiological parameters for 1.5 years.
According to biologists, these birds have not experienced problems with access to food, as they constantly fed the nursery staff, but they were forced to live outdoors and move Alpine frost. Changes in their physiological state, as hoped, the scientists were to reveal the secrets of their survival in such conditions.
As shown by these observations, birds survive the winter thanks to a simple trick that has mastered many mammals — they reduce the speed of your metabolism, heart rate and body temperature, allowing them to spend less energy to heat the body.
For example, in December and in January the rate of metabolism in geese was reduced by about 22% compared with the summer months, and their body temperature dropped about a degree Celsius.
In such as geese become more vulnerable to attack by predators, but predators are forced to live in similar conditions, which equalizes their chances of survival. As suggested by biologists and other bird, rarely migrating to the South, can use the same techniques for over-wintering in temperate and polar latitudes.