"Cock of the Plains"
Sage Grouse, Centrocercus urophasianus1
Meriwether Lewis first observed sage grouse at the mouth of the Marias River on June 6, 1805. Private John Shields was sent to kill one, but he missed his shot. They expected to see more of them, however, for "the Indians informed us they were common to the Rocky Mountains." The bird was new to science then, and plentiful throughout the western part of what is now the United States.
Since then the species has declined to the point that it may soon be listed by the U.S. Fish and Wildlife Service as Threatened, under the Endangered Species Act of 1973. Modern interpretations of the expedition's sage grouse field notes provide insights into the bird's vulnerability to changing habitats, and give clues to current management requirements necessary to arrest its decline.
The journals record sage grouse encounters from the mouth of the Marias River, up the Missouri to Camp Fortunate, along the trail to Lemhi Pass, along the Salmon River, down the Clearwater River, then to the confluence of the Walla Walla River with the Columbia. Lewis and Clark documented sage grouse abundance and distribution: "The Heath Cock or cock of the Plains is found in the Plains of Columbia and are in great abundance from the enterance of Lewis's river to the mountains which pass the Columbia between the Great falls and Rapids of that river." Thus we have a historic account of sage grouse range and abundance, both substantially diminished today. At the confluence of the Snake and Columbia Rivers on October 17, 1805, Clark killed "a Fowl of the Pheasent kind as large as a turkey. The length from his beeck to the end of its tail 2 feet 6-3/4 Inches, from the extremity of its wings across 3 feet and 6 Inches. the tail feathers 13 Inches long, feeds on grass hoppers, and the seed of wild Isoop," which is now called sagebrush.2
Artemisia tridentata Nutt.
Of the twelve species of the genus Artemisia listed in the USDA PLANTS Database, nine are still found in states through which the Lewis and Clark Trail passes. The abbreviation Nutt. following the name stands for Thomas Nuttall, the botanist who first described the big sagebrush, and gave it is scientific name. The genus, pronounced ar-te MEE-zee-uh, is named after Artemis, the Ancient Greek goddess of wilderness; the species, pronounced try-den-TAH-tah, refers to its three-lobed gray-green leaves.
Sagebrush is the critical component of sage grouse diet, and the distribution of sage grouse and big sagebrush overlap. Another important observation was that sage grouse are large birds. Large animals tend to be long-lived, with relatively low reproductive rates, and this is the case with sage grouse. This life style makes such animals especially vulnerable to predation.
Clark recorded the behavior sage grouse use to avoid predators—"they go in large gangues or Singularly and hide remarkably close when pursued, make short flights, &c."— along with their coloration: "The colour is an uniform mixture of dark brown reather bordering on a dove colour, redish and yellowish brown with some small black specks. in this mixture the dark brown prevails and has a slight cast of the dove colour at a little distance." In other words, sage grouse avoid predators through camouflage, singular dispersal and remaining hidden until the last moment of discovery, when they startle their attackers.
Clark's sage grouse description included an important anatomical feature: "the gizzard of it is large and much less compressed and muscular than in most fowls; in short it resembles a maw (stomach) quite as much as a gizzard." The gizzard functions to grind food before it enters the stomach. Most birds ingest small stones that are used in the gizzard to facilitate grinding hard foods such as seeds. The sage grouse evolved certain characteristics in association with its habitat, including a diet that consists largely of sagebrush, which, in turn, favored the evolution of a gizzard that is uniquely nonmuscular for a grouse.
Sage grouse have been described as a landscape species. That is, they use small areas of different habitat types for varying periods, and their presence may be used as an indication of the health of a landscape.
Sage grouse begin their life cycle by assembling on leks for mating. A lek is a bald area on ridges or similar openings in sagebrush country about the size of a football field where grouse assemble year after year between February and April. Here the males strut about, flaring their tail feathers to fan-shaped. Clark described: "the tail is composed of 19 feathers of which that in the center is the longest, and the remaining 9 on each side diminish by pairs as they receede from the center; that is any one feather is equal in length to one equa distant from the center of the tail on the opposite side. the tail when foalded comes to a very sharp point and appears long in proportion to the body." The cock puffs up a large, whitish air sack on its chest, makes a soft drumming noise, and parades about tail feathers displayed and air sack puffed up, hoping for a hen to take notice. Unfortunately for most cocks only one or two cocks do most of the mating. Sage grouse return to the same leks each year. Some leks have been in annual use for hundreds of years. Hens build nests, lay eggs, and incubate them under cover of sagebrush. When we look across a sea of grey-colored sagebrush it may appear uniform and monotonous, but by walking through good stands we may recognize they are second only to riparian areas for species diversity. The hen depends on grass and forbs between sagebrush for additional cover and protection from predators such as coyotes, ravens, raptors, and magpies.
Chicks can walk as soon as they are hatched. The hen generally leads the newly hatched chicks to a riparian area near a river, stream, or pond. The chicks focus on the energy- and protein-rich beetles, ants, and other insects at first and grow rapidly, becoming able to fly short distances in two weeks. Later the chicks consume more forbs. Within five weeks they're capable of sustained flight. The hens and cocks mostly eat sagebrush leaves. Later in the summer, when sagebrush zones dry out, sage grouse often move to moist meadows, riparian areas or higher elevations in habitats such as around aspen groves. In these areas the grouse may feed upon lupine, clover, dandelions, yarrow, and other soft-tissue foods. Sage grouse do not need free water if plant foods are succulent enough.
1. Centrocercus urophasianus is pronounced sen-tro-SER-kus YOU-row-faze-ee-AY-nus. The name of the genus is a combination of the Greek kentron, meaning point, and kerkos, tail. The specific epithet is from another Greek word for tail, oura, plus phasianos, pheasant. The noun pheasant was originally applied to a bird that was native to the valley of the Phasis River (now the Rioni River), which drains into the Black Sea from the Repubic of Georgia. In the time of Lewis and Clark the word pheasant stood for "a genus of gallinaceous birds," according to lexicographer Noah Webster (1806), and the explorers often used it in that sense. Gallinaceous then referred to "domestic fowls, or the gallinae"; the family Galliformes (Latin gallus, cock, and forma, shape) now includes pheasants, grouse, turkeys, quail, and all domestic chickens. Lewis and Clark are credited with the discovery of five gallinaceous birds in addition to the sage grouse: the Columbian sharp-tailed grouse, the dusky grouse, Franklin's grouse, the Oregon ruffed grouse, and the mountain quail.
The taxonomy of the sage grouse was written in 1827 by the biologist Charles Lucien Bonaparte (1803-1857), a nephew of Napoleon. Paul Russell Cutright, Lewis & Clark, Pioneering Naturalists (Lincoln: University of Nebraska Press, 1969), 157, 388; Raymond Burroughs, ed., The Natural History of the Lewis and Clark Expedition (paperback ed., with an introduction by Robert Carriker, East Lansing: Michigan State University Press, 1995), 211-15.
2. "Issop"—by which Clark meant hyssop (HISS-up)—is the Biblical name for an aromatic plant used in Hebrew rites of purification; today it refers to a woody Eurasian plant (Hyssopus officinalis) used in perfumes and as a condiment. In his Compendious Dictionary of the English Language (1806), Webster defined hyssop simply as "a genus of aromatic plants." Lewis and others in the Corps used the word in describing sagebrush. In northeastern Montana on May 12, 1805, Lewis saw "the wild hysop sage." Near the junction of the Lemhi and Salmon Rivers on August 27, 1805, Patrick Gass observed "a kind of wild sage or hyssop, as high as a man's head." Gass may have been referring to the plant now commonly called big sagebrush, Artemisia tridentata.
Supported in part by a grant from the Montana Committee for the Humanities