Daily Archives: December 7, 2014
Although sometimes regarded as “wilderness” birds, Ruffed Grouse have no aversion to living in close proximity to humans if the cover gives them adequate security. In some areas of Ontario, Canada – Ruffed Grouse are more abundant in remote wilderness forests. They thrive best where forests are kept young and vigorous by occasional clear-cut logging, or fire, and gradually diminish in numbers as forests mature and their critical food and cover resources deteriorate in the shade of a climax forest.
Ruffed Grouse response to man varies greatly across their range, depending upon their experiences. In southern Ontario generally they are usually quite elusive and difficult to approach. Yet they can still be killed with a canoe paddle or thrown stones in NW Ontario wilderness forests.
When the ground is bare of snow, Ruffed Grouse feed on a wide variety of green leaves and fruits, and some insects. They have also been known to eat snakes, frogs as well. But when snow covers the ground as it does for most of the winter across the major portion of their natural range, Ruffed Grouse are almost exclusively “flower-eaters,” living on the dormant flower buds or catkins of trees such as birches and pin cherry bush’s.
Known as solitary in their social behavior they do not develop a pair-bond between males and females, although there is usually at least one hen in the woods for every male. Young birds, especially, collect in temporary, loose flocks in the fall and winter, but this is not equivalent to the covey organization of the quails and partridges.
Male Ruffed Grouse are aggressively territorial throughout their adult lives, defending for their almost exclusive use a piece of woodland that is 6-10 acres in extent. Usually this is shared with one or two hens. The male grouse proclaims his property rights by engaging in a “drumming” display. This sound is made by beating his wings against the air to create a vacuum, as lightning does when it makes thunder. The drummer usually stands on a log, stone or mound of dirt when drumming, and this object is called a “drumming log.” He does not strike the log to make the noise, he only uses the “drumming log” as a stage for his display.
The drumming stage selected by a male is most likely to be about 10-12 inches above the ground, in moderately dense brush, (usually 70 to 160 stems within a 10 ft. radius) where he can maintain unrestricted surveillance over the terrain for a radius of about 60 ft. Across much of the Ruffed Grouse range there are usually mature male within sight in the forest canopy overhead.
Drumming occurs throughout the year, so long as his “log” is not too deeply buried under snow. In the spring, drumming becomes more frequent and prolonged as the cock grouse advertises his location to hens seeking a mate. Listen to an example at the top of this page.
Courtship is brief, lasting but a few minutes, then the hen wanders away in search of a nest site, and there is no further association between the male grouse and his mate – or the brood of chicks she produces. A hen may make her nest more than 1/2 mile from the log of her mate.
Nests are hollowed-out depressions in the leaf litter, usually at the base of a tree, stump or in a clump of brush. The nest is usually in a position which allows the hen to maintain a watch for approaching predators. Sometimes hens will nest under logs or in brush piles, but this is less common, and a dangerous location.
A clutch usually contains 8 to 14 buff colored eggs when complete. Eggs are laid at a rate of about one each day and a half, so it may take 2 weeks for a clutch to be completed. Then incubation, which usually commences when the last egg is laid, takes another 24 to 26 days before the eggs hatch. A nest has to be placed so that it will not be discovered by a predator during a period of at least 5 weeks.
The chicks are prosocial, which means that as soon as they have dried following hatching they are ready to leave the nest and start feeding themselves. Grouse chicks are not much larger than a man’s thumb when they leave the nest. They are surprisingly mobile and may be moving farther than 1/4 mile a day by the time they are 3 or 4 days old. They begin flying when about 5 days old, and resemble giant bumble bees in flight. The hen may lead her brood as far as 4 miles from the nest to a summer brood range during its first 10 days of life.
Although grouse broods occasionally appear on roadsides, field edges or in forest openings, these are hazardous places for young grouse to be, and broods survive best if they can remain secure in fairly uniform, moderately dense brush or sapling cover.
The growing chicks need a great deal of animal protein for muscle and feather development early in life. They feed heavily on insects and other small animals for the first few weeks, gradually shifting to a diet of green plant materials and fruits as they become larger. Chicks grow rapidly, increasing from about 1/2 ounce midgets when hatched to 17-20 oz. fully grown young birds 16 weeks later. That is a 38 to 46 fold increase in weight. At 17 weeks of age, a Ruffed Grouse is almost as large and heavy as it will ever be.
Biologists and others who want to age Ruffed Grouse rely upon certain peculiarities of the molt of the primary flight feathers. The booklet A Grouse in the Hand explains this aging procedure. And following the first complete molt by a 14 to 15 month old adult grouse, there are no known physical characteristics which reliably identify the age.
When about 16 to 18 weeks old, the young grouse passes out of its period of adolescence and breaks away to find a home range of its own. This is the second and last time that Ruffed Grouse are highly mobile. The young males are the first to depart, when they range out seeking a vacant drumming territory, or activity center, where they can claim a drumming log. Most young males find a suitable site within 1.8 mi. of the brood range where they grew up, although some may go as far as 4.5 mi. seeking a vacant territory. Many young cocks claim a drumming log by the time they are 20 weeks old; and once they have done so, most will spend the remainder of their lives within a 200 to 300 yard radius of that log.
Young females begin leaving the brood one or two weeks later than their brothers, and they normally disperse about three times as far. Some young hens move at least 15 miles looking for the place where they’ll spend the rest of their lives.
Occasionally a hen and her brood will remain together as late as mid-January, but this is unusual, and most groups of grouse encountered in the fall and winter are composed of unrelated individuals who gather together temporarily to share a choice food resource or piece of secure cover.
In fall and winter some inexperienced young grouse frightened by a predator or something else, crash into buildings, trees or through windows in a so-called “crazy-flight.” Sometimes they are evidently simply trying to take a short-cut when they can see through two large windows on the corner of a house. After all, young grouse in their first fall have never been confronted by something that can be seen through but not flown through, such as glass!