OUTDOOR WORLD BY DON MACLEAN
A few weeks ago I wrote about hibernation and how some animals, such as groundhogs, hibernate to get through the winter. I also talked about other animals, such as snowshoe hares, which change colour to protect themselves from predators while others make physical adaptations to survive.
I mentioned that ruffed grouse develop growths on their feet in late fall which serve as snowshoes to allow them to walk on the snow. I heard from several readers who wanted to learn more about it. The growths are known as pectinations and are little, comb-like fleshy tissue which grows along the scales of their toes. In addition to helping them walk over deep snow biologists also believe the larger surface areas help grouse grip tree branches as they feed on tree buds during the winter. They appear in the fall and remain throughout the winter, dropping off in the spring.
There is no question that ruffed grouse, or partridge, as most of us know them, have adapted to life in a tough environment. I have a friend who thought the partridge should have been chosen as our provincial bird instead of the osprey. His complaint was that the osprey took off when the going got tough in the winter while partridge toughed it out. In defence of ospreys, they are a magnificent bird which depends on fish to survive so, unless they take up ice fishing, they have to move to open water, or starve.
In addition to their physical transformation for winter, grouse have several other behaviours which allow them to survive in a harsh environment. One is their habit of diving into snow banks during the night to protect them from the cold. If you have ever walked through the winter woods and been surprised by a grouse flying out of a snowbank you will know that this can be an exciting experience. Winters that have lots of fluffy, deep snow are ideal for grouse so they should be doing well this winter. If there is little snow, or the snow has a heavy crust, grouse will try to find cover in spruce and fir thickets but being out in the open may make them vulnerable to attack from hawks and owls. Grouse mortality can vary greatly from year to year with bad winters being one of the major factors impacting survival. Mortality rates are high and few grouse live to be older than five or six years.
While they feed mainly on the ground for three seasons of the year on insects, seeds and fruit, winter weather forces them to look upward for their food. Winter evenings are when you will often see grouse, their feathers puffed up to insulate them from the cold, feeding on the buds of birch, alder and poplar. If they survive the winter, another interesting trait grouse have is the drumming done by males during the spring to attract females. I often hear drumming grouse when I am trout fishing in the spring so I am anxiously waiting for the day when I will hear it again. But that will be a topic for another column.
Don MacLean is an outdoor writer and biologist who lives in Pictou County.