Did You Know?
The range of sage grouse today covers 186 million acres in 11 western states and two Canadian provinces. However, three-quarters of the birds inhabit just 27 percent of the range. That’s why the Sage Grouse Initiative emphasizes restoring sagebrush grasslands in the core area—the places where the breeding populations are highest and conservation benefits the largest number of birds.
A Bird of Sagebrush Ecosystems
Sage grouse are linked to sagebrush ecosystems of western North America covering 11 western states: Washington, Oregon, California, Nevada, Idaho, Montana, Wyoming, Colorado, Utah, South Dakota, and North Dakota, as well as the Canadian provinces of Alberta and Saskatchewan.
Historic versus Modern Range
Historically sage grouse likely ranged over 14 western states and three Canadian provinces. The birds have been extirpated from Arizona, New Mexico and Nebraska, as well as British Columbia. Throughout the twentieth century and into the twenty-first, the birds declined as their range dwindled from cultivation, loss of sagebrush, and other alterations.
Click here: animated map of historic versus modern range
The sage grouse fossil record dates the bird to the Pleistocene era. The few fossils unearthed overall suggest a relatively recent origin.
Migration: Why do some populations move and not others?
Unlike some migratory birds that may fly thousands of miles between breeding and wintering grounds, sage grouse migrate as little as possible. They’re big lumbering birds with an awkward flight. Despite their physique, some sage grouse do fly impressively far – like the Saskatchewan population that winters 70 to 100 miles away in Montana. Those birds have no choice but to fly south away from deep snow to find accessible sagebrush.
Some sage grouse may be residents throughout the year, when they find favorable conditions. Other birds fly between winter, nesting, and summer areas – in various combinations. Factors affecting whether birds migrate include gender (Colorado females tend to move twice as far as males for example), behavior, seasonal habitat quality and placement, and the weather.
Birds are highly attuned to weather conditions. In a mild winter, sage grouse may choose to fly to their nesting grounds in midwinter. If snow comes early in the fall, sage grouse move more quickly to wintering grounds.
One question that has puzzled researchers is why some birds migrate farther than they need to fly to find suitable habitat. The likely causes are site fidelity and young birds dispersing to new terrain.