Mammal Adaptations During Seasonal Climate Change
Arctic Reindeer
Life above the Arctic Circle is not easy — cold, wind, snow, a couple months of total darkness — but the creatures that live there have evolved to handle the harsh conditions. Arctic reindeer, for instance, have thick coats with two layers of fur. The arctic reindeers eyes can also adapt and change in colour through the seasons from gold through to blue to help them better detect predators.
The color shift isn’t the only change in the reindeer eye; winter also brings a reduction in the spacing between collagen fibers in the tapetum lucidum and an increase in the pressure within the eye. This pressure increase occurs because in winter the eye stays fully dilated to let in as much light as possible.
Molting
Losing body hair is a major way that mammals—most of which are covered with fur—cope with heat. In winter, animals in temperate zones put on heavy coats for combating frosty cold and biting winds, but in summer they need lighter wear. Hormones in the body cause their dense winter coats to fall off, usually in patches, to be replaced with a lighter summer coat. Below are images of a bison during the hotter summer season and a bison in the cold winter, with different fur coats.
Life above the Arctic Circle is not easy — cold, wind, snow, a couple months of total darkness — but the creatures that live there have evolved to handle the harsh conditions. Arctic reindeer, for instance, have thick coats with two layers of fur. The arctic reindeers eyes can also adapt and change in colour through the seasons from gold through to blue to help them better detect predators.
The color shift isn’t the only change in the reindeer eye; winter also brings a reduction in the spacing between collagen fibers in the tapetum lucidum and an increase in the pressure within the eye. This pressure increase occurs because in winter the eye stays fully dilated to let in as much light as possible.
Molting
Losing body hair is a major way that mammals—most of which are covered with fur—cope with heat. In winter, animals in temperate zones put on heavy coats for combating frosty cold and biting winds, but in summer they need lighter wear. Hormones in the body cause their dense winter coats to fall off, usually in patches, to be replaced with a lighter summer coat. Below are images of a bison during the hotter summer season and a bison in the cold winter, with different fur coats.
Hibernating
When autumn turns to winter and the air becomes frigid, bears go into a deep sleep called hibernation. Animals like the bear would find it extremely difficult to find enough food during winter, and therefore go into hibernation. There are physiological changes that occur when a bear goes into hibernation.
When autumn turns to winter and the air becomes frigid, bears go into a deep sleep called hibernation. Animals like the bear would find it extremely difficult to find enough food during winter, and therefore go into hibernation. There are physiological changes that occur when a bear goes into hibernation.