October is grouse season. The woods are orange, red and yellow, and as the nights get colder, more birds will start showing up along the roads.
While some hunters are simply happy to have game meat for dinner, there are certainly those inquisitive folks who want to know more about the birds they harvest. They dig into the crop to determine what the bird was eating and want to know its age and sex.
Knowing whether a grouse was a juvenile or adult and a male or female can give hunters a little more insight into the birds they are finding in the woods. It can also help them better understand the grouse population in the areas they hunt.
The feathers provide several clues that can be used to determine a harvested ruffed grouse’s sex and whether it is a juvenile or adult.
Determining sex of a ruffed grouse
Start with the rump feathers above the base of the tail. One white dot at the tip of the feather indicates a female, while two white dots indicate a male.
Another method is to pull one of the two central tail feathers and measure it. A fully grown feather 6 inches or longer indicates a male, while one shorter than 5½ inches indicates a female. Tail feathers measuring between 5½ and 6 inches cannot reliably determine the bird’s sex on their own.
For birds with central tail feathers measuring between 5½ and 5⅞ inches, the Ruffed Grouse Society describes another method. Compare the central tail feather with the second primary flight feather. If the two are about the same length, the bird is a female. If the tail feather is more than ⅜ inch longer, the bird is a male.
The dark band near the end of the tail can provide another clue. About 77% of males have an unbroken dark band, according to the Ruffed Grouse Society, but some males have broken bands, so this characteristic should not be used by itself to determine sex.
Determining age of a ruffed grouse
Examine the ninth and 10th primary wing feathers. Juvenile grouse have narrowed, pointed feathers with frayed edges, while adult grouse have rounded feathers with smooth, intact edges.
Early in the season, while some adult grouse are still molting their primary feathers, you can also determine age by looking at which feathers are growing. Adult grouse replace their primary feathers in sequence, while juveniles are growing their first set. A growing ninth or 10th primary indicates an adult, while a growing seventh or eighth primary indicates a juvenile.
There is an important limitation when aging grouse: You can distinguish a juvenile from an adult, but you cannot determine the exact age of an adult grouse from its feathers. After the first complete molt of a 14- to 15-month-old adult, there are no known physical characteristics that reliably determine the bird’s age, according to the Ruffed Grouse Society.
A helpful video by the RGS demonstrates these techniques on birds in hand.