Grouse Genes Don’t Lie
Many Montanans are devoted to the blue grouse. Some have enjoyed memorable hunting experiences, while others recall Sunday meals around a cast iron roaster of savory grouse breasts smothered in mushroom gravy.
Now there is some surprising “news.” Blue grouse are no longer blue, they’ve been renamed “dusky grouse.” That’s right—their name has officially changed.
The decision isn’t actually news. In 2006, the American Ornithologists’ Union’s committee on classification and nomenclature announced that the genus Dendragapus is made up of two species. New DNA evidence published in 2004 showed that the grouse of the Rocky Mountains and those of the Pacific Coast Ranges and Sierra Nevada inhabit separate, isolated habitats with no gene flow between the two populations. As a result, dusky and sooty grouse have genetically diverged from each other. Today we have the dusky grouse of the Rocky Mountains and the sooty grouse of the California and Sierra Nevada mountains.
A possible third population is in the making as a result of a divergence, notable on a DNA level, between the northern and southern dusky or blue grouse populations.
It is satisfying to see DNA-based research agree, in this case, on an earlier generation’s careful observations. Bird specialists first backed splitting the two grouse populations in 1931, then quickly reversed the decision amid noisy controversy.
They had made their case on observable differences between the grouse of the Rocky Mountains and birds further west. However, it was the ability, in this decade, to take the bird apart down to its DNA that finally carried the day.
Some of the observable differences between the sooty and dusky grouse include the bare skin patches that show on males. The patches are yellow on the sooty grouse and tend to be red in the dusky grouse. Sooty and dusky grouse also differ in the presence or absence of a distinct tail band, and in the color of their downy young, their mating calls and other courtship behaviors.
While the name dusky grouse doesn’t conjure a mountain setting the way the name blue grouse does, the mountains are their home. They feed on the needles of coniferous trees in the winter and are found in regions with high elevation forests intermixed with open meadows. Dusky or blue grouse don’t migrate long distances either. Their movement tends to be from one altitude to another, between summering and wintering habitats.
Because of new technology now available for DNA analysis, reclassification of entire genera, tribes, subfamilies and even families will become more frequent, scientists say. Despite this work, the blue grouse will probably carry that name in Montana for years to come.
There is power in a name. For many of us, when a blue grouse appears in autumn’s brassy, cured grasses, it awakens feelings and memories that only those two words can express.