- 22–29.5 in
- 49.4–102.3 oz
- Larger than a Ring-necked Pheasant; smaller than a Wild Turkey.
- Tétras des armoises (French)
- Over the harsh winter, sage-grouse actually manage to gain weight and strength in preparation for the breeding season by feeding on the leaves of sagebrush. They get water from feeding on snow.
- In preparation for a strutting display, male Greater Sage-Grouse can gulp and hold a gallon of air in a pouch of their esophagus. By squeezing it out with force, they begin their display.
- Although many male Greater Sage-Grouse may display at a lek, only one or two males get picked by a majority of the females for mating. Scientists have recorded a single male copulating 37 times with 37 different females—and coincidentally the whole thing took 37 minutes. This isn’t all that uncommon for the top males at a lek. Most of the females mate with the same one or a few males—putting intense pressure on males to be the best.
- The sound from the males’ booming display is actually loudest off to each side, not straight ahead. That’s why you may see displaying males standing to the side of a female instead of in front of her.
- Like many other grouse species, the Greater Sage-Grouse male plays no role in the raising of the young. Males display on dancing grounds known as leks. Females visit the leks to obtain matings, and then go off to raise their brood by themselves.
- Traditional lekking grounds may be used for years.
- Sage-grouse have a specialized stomach that digests the tough sage-brush, their main food.
- Greater Sage-Grouse can live up to 9 years in the wild, but more often 3–6 years. Females tend to be longer-lived, due to high predation of males on leks.
Greater Sage-Grouse live only on the sagebrush steppe of western North America, and they use several types of sagebrush habitat in different parts of the year. They usually nest in areas with relatively dense cover from big sagebrush (Artemisia tridentata), although they also use areas with rabbitbrush, greasewood, and grassy areas. Leks are located in clear areas such as broad ridgetops, grassy swales, dry lakebeds, and sometimes recently burned areas. Adult hens lead their growing chicks to areas with good forage, including irrigated pastures, wet meadows, and alfalfa fields, in addition to sagebrush.
Sage-grouse eat leaves, buds, flowers, forbs, and insects. Leaves (primarily of sagebrush) dominate the diet throughout most of the year. However, in the first three weeks after hatching, chicks cannot digest sagebrush, and forbs and various insects (beetles, grasshoppers, and ants, especially) make up the bulk of the juvenile diet. Dandelions and other forbs are important for females as they prepare for laying.
- Clutch Size
- 4–11 eggs
- Number of Broods
- 1 broods
- Egg Length
- 2.2–2.3 in
- Egg Width
- 1.5–1.5 in
- Incubation Period
- 25–29 days
- Nestling Period
- 1 days
- Egg Description
- Variable shades of olive-buff or pale greenish, with fine, darker markings.
- Condition at Hatching
- The downy, well-camouflaged chicks are precocial, able to feed themselves within minutes of hatching. Typically able to fly weakly after 10 days, and strongly after about 5 weeks.
Females make bowl-shaped nests scraped into the soft soil and lined with leaves, grasses and forbs, small twigs, and feathers that the female plucks from her breast. The cup interior is about 8 inches across and 2–4 inches deep.
Females do all the nest-building, incubation, and raising of the chicks without any help from males. They place their nests on the ground, usually under a sagebrush shrub and sometimes under tufts of grass within dense patches of shrubs. Nests tend to have at least two directions that are not heavily vegetated, which presumably function as possible escape routes for incubating females.
Greater Sage-Grouse offer one of the best examples of the breeding system known as lekking—where males gather in a confined area to perform courtship displays for females. Males are intensely territorial on leks, defending areas just a few yards across. Females visit these leks to size up the displays and choose their mates. Despite all the male brawn on display, it’s the females that are in charge. When a female chooses a male she crouches, spreading and drooping her wings slightly in an invitation to the male. Many females end up mating with the same male; most of the other males on the lek wind up with no mating opportunities at all. After mating, males have no further contact with the female or the young.
From roughly March through May, males gather on leks at dawn. There they perform a complex, highly choreographed display that is among the most extraordinary wildlife sights in North America. With tail fanned and erect, a male repeatedly gulps air while stepping forward; then forcefully releases it. Standing tall, with inflated chest held high, the male sweeps his wings across his white breast, creating a swishing noise. He tilts his head back, rapidly inflating, bouncing, and deflating the yellow, balloon-like pouches on his chest. The outward popping of these bare pouches creates a series of echoing pops. These displays are performed almost continuously, and up to 10 times per minute, for several hours in the early morning.
Rival males often find themselves locked in a standoff, facing head to tail a foot or two apart. During these threat displays, males crouch low and bob quickly, giving a low, repeated clucking. These standoffs may boil over into battering attacks with the wings; they may drive away or exhaust they opponent, but rarely cause serious injury.
Greater Sage-Grouse are strong, fast fliers (up to 50 mph in level flight), but endurance is not a strong suit. Sustained flights rarely exceed a few miles. Most of their movement is on foot, typically averaging less than a mile per day.
Greater Sage-Grouse have declined greatly from presettlement estimates as high as 16 million to as few as 200,000 today—reflecting the widespread loss, alteration, or fragmentation of the vast sagebrush steppe that they depend on. Since the late 1960s, numbers have declined by an average of 2.3 percent per year (reflecting a cumulative decline of 64 percent in that time), according to the North American Breeding Bird Survey. Partners in Flight estimates the global population of breeding individuals at 150,000, with 94 percent in the U.S. and 6 percent in Canada. They rate a 15 out of 20 on the Continental Concern Score and are on the 2014 State of the Birds Watch List, which lists species most in danger of extinction without significant conservation action.
Considering the species’ dependence on different areas in different seasons, the need for corridors of suitable habitat to move between those areas, and the fact that sage-grouse reproduction requires social interactions within sizeable groups, their sensitivity to habitat fragmentation is extreme. Research suggests that a population of sage-grouse tied to a single lek might depend on more than 75,000 acres of unbroken sage, while a dispersed population with multiple nearby leks may use 250,000 acres.
Even small amounts of disturbance (such as patches of cultivated land, telephone poles and utility lines, or minor roads) reduce sage-grouse populations. The disturbance associated with infrastructure, construction, and operation of drill pads and wells also has measurable, negative impacts on lek attendance and population size. Fragmentation of sagebrush habitat has reached a point where less than 5 percent of sagebrush habitat lies more than 1.5 miles from a paved road, and this is a major obstacle in striking a balance between the realities of development and the needs of sage-grouse.
Resident (nonmigratory) to short-distance migrant, often moving relatively short distances (20 miles or so) between wintering and nesting areas. Females may lead their chicks to summer feeding areas in higher elevations or wet areas.