Throughout the year, sage-grouse have various habitat needs, meaning that they must move to different areas in order to survive. Sage-grouse have been known to migrate over many miles in order to find the right seasonal habitats.
Habitat use is related to sage-grouse activities during each season of the year, their reproductive process, and their habitat requirements during different life stages.
Breeding & Nesting (March-June)
Spring is the mating season for sage-grouse. The species exhibits a polygynous mating system, meaning one male will mate with multiple females. Females choose their mate while attending annual gatherings on communal breeding grounds, known as leks. Males try to attract females by performing an elaborate strutting display, much like a dance, and by making a “plopping” sound with their inflatable chest air sacs. Sage-grouse typically gather on these leks between March and early May, depending on the location and elevation. There can be as few as two and as many as 100 birds on one lek at any given time.
Leks can be found at a variety of locations, but generally are in open areas adjacent to sagebrush, so the male sage-grouse have room for their dancing display. Leks could be in meadows, openings created by fires or roads, areas of low sagebrush, or dry lake beds. Most leks are traditional and used year after year.
Nesting & Early Brood-Rearing (May-June)
A female sage-grouse camouflaged on her nest
After mating has ended, the female (hen) leaves the lek in search of a nesting site. Though studies in southeastern Idaho have shown that hens often nest within 2-3 miles from the lek, the distance can vary from one region to another. Some hens have been observed moving more than 11 miles to nest.
The sage-grouse nest is a bowl-shaped depression on the ground comprised mostly of vegetation such as dead grass. The nest is typically located under a sagebrush shrub, but can be under other common steppe shrubs such as bitterbrush, yellow rabbitbrush, or rubber rabbitbrush.
Sage-grouse lay a relatively small clutch size (number of eggs) averaging six to seven eggs, and if their nests are disturbed, they usually won’t create another nest and lay more eggs. This means that sage-grouse have one of the lowest reproductive rates (how they produce more birds) of any North American game bird. Eggs can be olive to pale green in color, with small dots of brown. After sage-grouse chicks hatch, the hen and chicks will stay in the vicinity of the nest for up to three weeks.
Nesting & Early Brood-Rearing Habitat Characteristics
In order for sage-grouse to survive, they must be able to nest and raise their young.
Greater sage-grouse require a large area of sagebrush habitat, as well as a substantial understory (the area underneath sagebrush) of grasses and forbs (flowering broad-leaved plants) for their nesting and early brood-rearing (raising their chicks) habitat. Sage-grouse chicks need sagebrush, grasses and forbs in order to protect themselves from predators and have access to food without exposing themselves to attack.
Sage-grouse eggs on a nest
Late Brood-Rearing (July-Sept.)
Typical late summer habitat for hens and broods when riparian areas become important foraging areas
As temperatures rise in the summer months, grasses and forbs on rangelands start to dry out. During this time, the hen and brood
(chicks) will move out of their nesting habitat to find more forbs and insects. They will either move to areas higher in elevation where conditions are cooler and wetter, or to areas where water collects. They can frequently be seen in agricultural fields, wet meadows, and riparian areas near sagebrush cover. Some sage-grouse have been known to travel as far as 50 miles to reach their summer habitat.
Fall & Winter (September-March)
Sage-grouse winter range
Fall habitat for sage-grouse can vary greatly. During this time of year, sage-grouse will continue using wet meadows, riparian areas (along or near the bank of a river) and irrigated fields until their food source of forbs dries up or is killed by frost. During this time, sage-grouse will move to sagebrush areas because they need to eat sagebrush leaves in order to survive.
Sage-grouse spend the winter in sagebrush habitats because they rely on the plant for both food and shelter. They tend to choose habitat where sagebrush is between 10 and 14 inches above the snow level, so they can find food to get them through the winter months.
Migration in sage-grouse appears to vary by individual bird populations. Birds from some populations have been observed showing no significant migration between seasonal habitat during the course of the year. Other populations have been observed showing a two stage migration, with birds moving from their winter/breeding habitat to their summer range. Still other populations have shown a three stage migration, moving from winter to breeding, then to summer ranges. Some populations have been recorded traveling distances as far as 100 miles. In Idaho, most sage-grouse populations tend to be migratory. The exact reason for migration is not known, but tradition and habitat availability in a given geographic area likely play a role.