Pounding sound nothing to grouse about
A couple of years ago, I was hiking in the Forest Creek area in the Applegate shortly after dawn. My heart started to race, pounding louder and louder in my chest. I feared a serious health issue, and I was alone. Would I be able to make it back to the car in time? And then suddenly, the pounding stopped.
A moment later it became clear I was not about to die. I had been fooled one more time by a forest bird, the ruffed grouse. I have experienced this moment of anxiety at least a half-dozen times over the years. You would think I would remember, but it’s a sound you feel more than hear. When it feels like it’s coming from inside your chest you react before you think.
The ruffed grouse is one of two grouse found in Jackson County. It is the smaller and less common of the two and is mottled brown with black “shoulders” and a small crest. The tail is either light gray with a black terminal band or rich brown with the same black terminal band. I have only seen birds with gray tails locally. The ruffed grouse tend to live in low-lying areas in denser vegetation along creeks.
The other species is the sooty grouse, formerly lumped with the dusky grouse and together called the blue grouse. The sooty grouse is larger and grayer and is most often found on hillsides above the valley floor on up to timberline.
When seeking mates, the sooty grouse typically finds a large limb high in a tree and calls with a deep booming “hoot.” Many field biologists have been fooled into thinking the call is from a great gray owl. The grouse is sometimes called the “great gray grouse,” tongue in cheek, as a result.
The ruffed grouse male does not hoot or call when attempting to attract females. Instead, it hops up onto a log with good resonance or other small rise, and when ready it quickly claps its wings to its body. The trapped air produces a thump of very low frequency. It repeats the action over and over, faster and faster, until it blends into a single note. When the brief performance is over, it pauses. Then the routine is repeated until hunger wins out and the male continues with its day.
It has been claimed that the sound produced by the ruffed grouse is such low frequency that it cannot be heard by hungry great horned owls. The hooting of the great horned owl is also of low frequency, but not as low as the drumming of the ruffed grouse. Still, I wonder.
Sounds of different frequency don’t all travel equally well through the “cluttered” environment of a forest. Branches and leaves tend to quickly absorb higher-frequency sounds. Low-frequency sounds carry much farther before fading out. The low-frequency sounds produced by these grouse are well suited for life in the forest. Other birds that live beneath the canopy in the forest also tend to have low-frequency calls and songs compared to birds that live near the treetops or other more open environments.
Stewart Janes is a retired biology professor at Southern Oregon University. He can be reached at firstname.lastname@example.org.