During the winter months in northeast Ohio, snow isn’t the only thing that is white. When the snow flies…. some animals turn white too! Say what? As we all know birds, insects, and animals have different strategies when dealing with winter in northeast Ohio. Most birds migrate south, some insects bury themselves in the ground, some reptiles and amphibians bury themselves in the mud, some animals grow thick fur, and some hibernate. As it turns out, there are 21 mammals and birds that actually turn white in the winter. A few live-in northeast Ohio. At first glance one would think it is for camouflage, but it seems there is more to it than that. Conventional wisdom would dictate that if keeping the animal hidden in the snow was the reason for this coloration, more animals would be white during the winter. While white coats can provide camouflage in a snowy landscape, researchers have found a more practical basis. There is a theory that a light-colored coat may keep animals warmer. With less pigment in the hair shaft, there is room for more air, which traps body heat and provides insulation to the animal. The color change is thought to be at least partially linked to day length. As the days shorten, receptors in the eye transmit that information to the brain, stimulating the replacement of brown hair to white, starting with the extremities. The reverse is true in the spring as the days grow longer. The white fur is replaced by the darker brown fur. This is called molting. Birds go through a similar process each year prior to breeding season.
In northeast Ohio you can find several small mammals that grow white winter coats, also known as a leucitic phase. Three weasel species, including the short-tailed weasel, the long-tailed weasel, and the least weasel turn white. Snowshoe hares found in Ashtabula, Lake and Cuyahoga counties get a new white coat in winter. Although not found in northeast Ohio, Artic fox, Ptarmigans, and Lemmings also turn white in the winter. Some animals in the artic stay white year-round, the Polar Bear, Snowy Owl, and Gyrfalcon are a few examples. Since temperatures stay cold and there is always snow cover, there is no need to molt.
One study has shown that global warming may be a major threat to the survival of these animals. As the northern areas warm, the usual snow cover associated with shorter days is not there. As a result, their fur begins to turn white due to the shortening daylight and they stick out like a sore thumb in the drab brown landscape. Easy picking for hungry predators. For the study, the researchers first collected coat color and location data for more than 2,500 live animals and museum specimens spanning 60 countries. They then analyzed this data using modelling to study the molting behavior of animals living in different parts of the world. The researchers found that not all individuals will molt in the winter. The chances of an animal molting depend on the landscape in which they live. The snowier the landscape, the higher the chance an animal will turn white in the winter. These brown-coated animals will be more likely to survive winters with less snow cover and pass on their genes to their offspring. Over time, this would increase the proportion of animals with brown winter coats, allowing the population to adapt and ultimately survive in environments with less snow.
Moral of the story…. nature finds a way to survive and adapt…. usually! Time will tell as the climate continues to change.
