Sagebrush habitat

The key to conserving the species

Portions of 14 Western states once provided year-round food, shelter and breeding grounds for the Greater sage-grouse.  Pressure from urbanization, wildfire, recreation, energy development, livestock grazing, invasive weeds and disease have shrunk these historical habitats, such that only portions of 11 states still have lands for the bird to call home.  As a result, their numbers have declined by about 40% since the 1970s.  As few as 200,000 may be left.

As manager of more remaining habitat than any other government agency, the BLM is taking a coordinated, Bureau-wide approach to protecting intact habitat, avoiding or minimizing further habitat loss, and managing habitats to restore or maintain favorable conditions.

The setting for life-history

Sage-grouse depend almost completely on sagebrush for food and cover.
While the birds use sage-steppe habitat year-round, it is critical in winter and spring.

Sge-grouse spend long winters sheltering under mature stands that stay exposed at least 10 inches above accumulated snow.  More than 98% of their winter diet is sagebrush leaves.

During the spring, sagebrush habitats are the place for breeding.  Males and females congregate at leks – flat, open areas surrounded by sagebrush.  After mating, females nest and then raise their broods beneath sagebrush overstory.

Sage-grouse are creatures of habit: they often return to the same leks year after year, and show little ability to adapt to habitat changes of new human disturbances.

Changes or new disturbances can cause indirect habitat loss beyond the acres directly involved.

Birds may begin to avoid affected areas but not be able to find or utilize substitute habitats.  Lands adjacent to the affected acres may not be as productive as traditional areas.  Direct and indirect habitat loss can continue during the life of a development project or in spite of restoration or mitigation efforts.

Mitigation and restoration

The life-history of sagebrush mirrors that of the sage-grouse in a way that makes habitat restoration and mitigation challenging: the plant (Artemisia tridentata) also seems to recover slowly from change.

Research shows that it takes 25-75 years or more for mountain sagebrush to recover to pre-disturbance condition.  Wyoming big sagebrush apparently recovers even more slowly – in the range of 50-120 years on paper, and with limited success in practice.

Along with the extensive timeframe, repeated seedings and plantings may be needed to restore full ecological function.  In the meantime, displaced local sage-grouse populations may be permanently disrupted.