I first heard of the spruce grouse in third year, when I took wildlife biology. If you’ve been following my blog since the beginning, I’m sure you remember that wildlife biology involved doing a presentation on your species of choice. Mine was the small Indian mongoose. One of the best presentations I saw was another student’s on the spruce grouse.
Spruce grouse are found all over northern North America, from southern Alaska to the Northwest Territories, and from British Columbia to Quebec. These birds are found in coniferous forests, where spruce, fir, and cedar tree grow. They are heavily dependent on tree cover, and prefer areas full of young trees that have branches that droop to the ground.
Spruce grouse are not super big, growing to 38-43 cm, with weights of up to 650 grams. Both sexes are mostly brown or black with some white feathering scattered about. Males are larger than females and have a bit more presence — their plumage is just more impressive looking and they have cool red patches of skin about their eyes.
One of the coolest things about spruce grouse is what they eat. While evergreen needles might not look too tasty, that’s what makes up the majority of this bird’s diet. During the summer the spruce grouse supplements its diet with berries, insects and fungi, but in the winter needles are the only thing it gets.
To consume this diet, spruce grouse require some digestive adaptations. They have large caeca in their intestines, which are pouches where bacterial fermentation can take place. These pouches enlarge during the winter, when the birds’ diets are composed purely of nasty pine needles. Their crop (where birds store food) is also very large, and spruce grouse can store up to 10% of their body mass of needles in the crop. This allows the birds to slowly digest the needles overnight. Like many other birds, grouse ingest small rocks which help break down food mechanically in the gizzard. See, birds don’t have teeth, so these rocks are basically a replacement for chewing.
Reproduction in spruce grouse occurs from May to July. Male grouse will defend a territory in which they display to females. They use a variety of displays, including tail flicks, neck snaps and stomping. Once she has mated, the female will build the nest on the ground under the cover of vegetation, either in a bush or under low-lying tree branches. The nest is simply a shallow depression in the ground, and the grouse lay 4-7 eggs.
After about three weeks, the eggs hatch and chicks begin to walk around immediately after birth. At young ages, the chicks are not capable of digesting pine needles, so they submit mainly on insects until they are older. At a week of age they begin to eat huckleberries, and only start eating needles in the fall.
Though they can fly, spruce grouse are not great at it and prefer to walk. In the winter this can become difficult, due to snow cover, but grouse have a solution for this: they grow extensions on their feet that increases the surface area of the foot, acting like snowshoes. Spruce grouse use the snow in winter as insulation, digging burrows in the snow to keep warm. They can spend up to 22 hours in a day in their snow roosts.
Spruce grouse are sometimes known as ‘fool hens’, due to their tame behaviour around humans. Often when captured and released, spruce grouse will only wander a couple of feet away before resuming foraging. Some hunters won’t hunt for spruce grouse because they are too easy to kill. Still, I don’t think these birds are that foolish, considering they survive in one of the harshest environments on one of the most difficult to digest diets. But I’ve never met a spruce grouse, so I could be wrong.
Cover image source: http://www.summitpost.org/spruce-grouse/626269