SCISUN: Making a Change for the New Year   Leave a comment

This time of year, many of us live in a snow-covered winter wonderland. Unless you’re the one who has to clear the ice from the sidewalk, then maybe it’s not so much of a wonderland. Wildlife also have to deal with the change in weather, and while most plants become dormant; some animals migrate to warmer climates and others hibernate; there are a few animals who remain alert and active all winter, through rain or snow or even at night. Of course when you’re a predator, trying to sneak up on food; or even more importantly for prey, who are trying to avoid the predators, how do you hide when you’re brown or grey or tan, and all the world is snowy white?

For a few animals, fitting into the winter landscape is no problem at all. The Arctic Fox (Vulpes lagopus) ; Arctic Hare (Lepus arcticus) ; Ermine (Mustela erminea) – a type of weasel; Reindeer (Rangifer tarandus) ; and Ptarmigan (Lagopus muta) – (no we didn’t make that one up. It’s a kind of ground-living bird) are all examples of animals that change, each winter, from their usual browns and greys into new coats of white. Of course, the animals don’t one day decide they want to look different and suddenly change color, just like you and I might change clothes. (And it’s also why wildlife never, NEVER need bigger closets). The color variations are a result of changing weather, temperature, food supply, amount of sunlight each day and even the position of the sun in the sky. Then slowly, over a few weeks starting in the Fall, as each hair or feather naturally falls out, it’s replaced with a new white hair or feather until the entire animal is white, or at least mostly white. It’s not unusual for there to still be spots of black or grey, or other distinctive color patters for individual animals or even among different species.

But white isn’t just for camouflage, any more! Scientists have found the white hairs and feathers are not actually colored white, but are actually almost transparent with very little color at all and only appear white because the hundreds of thousands of hairs on each animal is so dense. In place of color pigment, the cells of hair and feathers are hollow, and filled with air, which acts as insulation and keeps the animals warm in the cold winter air. In fact some of these winter-hardy animals dig burrows and nests into and under the snow, which itself acts as insulation and keeps the wildlife warm and comfortable. Although just how warm anyone can be under a blanket of snow, is something we wouldn’t want to try.

Reindeer (Rangifer tarandus)

“Maybe I didn’t wear the right coat for this trip…..”

In the Spring, when the temperature starts to warm; there’s more sunlight every day; and the weather becomes more comfortable, the color-changing process reverses and as white hair and feathers fall out they’re replaced with the ‘usual’ browns and tans and greys and blacks the animals wear most of the year. But strangely, and for reasons no one knows, among these winter-ready color-changers there are a few individuals who only partially change to white; or turn only a lighter shade of their earth-tone colors, or even don’t change at all and remain their usual dark colors all winter. And every winter, they do just fine. Proving that not everyone is a slave to fashion.


Michonne Says:  Marmots never change color. We’re pretty just the way we are.  But if I ever did become another color, I’d like to be field-flower yellow.  With orangey eartips.

Posted December 30, 2012 by ECOVIA eco-adventure® in SciSun

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