Habitat Atlas for Wildlife at Risk
Sage Thrasher
Oreoscoptes montanus

• Length: 18 cm; slightly smaller than American Robin.
• Brownish-grey back with buff white underparts, heavily streaked with brown.
• Yellow eye, white tips on outer tail feathers and two narrow white bars on wings.
• Small size, shorter tail, shorter bill and striped breast distinguish it from other typical western thrashers.

Status:

British Columbia Red List
Canada: Endangered

Special Significance

The Sage Thrasher is one of the rarest birds in Canada. Prior to 1930, there were 30 or more nesting pairs at up to six sites; in recent years, only 4 - 10 pairs have been seen at one or two sites. Over the past 70 years, there has been an estimated 50 percent loss of habitat for the Sage Thrasher. Heavy grazing and clearing of sagebrush to improve range conditions has seriously affected the availability of suitable nesting areas. The preservation of remaining Sage Thrashers depends on the careful management of remaining large tracts of dense sagebrush habitat. Heavy grazing of sagebrush sites should be avoided, and areas cleared of sagebrush should be restored whenever possible.

Distribution

• In Canada, Sage Thrashers breed regularly only in the southern Similkameen and Okanagan valleys, specifically in the White Lake area and near the Chopaka border crossing.
• Occasionally breeds in North Okanagan and Thompson valleys (one record in each) as well as southern Alberta and Saskatchewan.
• Elevational range is from near sea level to 950 metres; breeds from 300 to 500 metres.

Habitat

• Sage Thrashers prefer large, open tracts of dry shrub/grassland with dense stands of big sagebrush, antelope-brush and rabbit-brush.
• Stands of large sagebrush are required for both nesting and foraging; shrubs need to be tall and sturdy to support bulky nests and dense enough to provide shade and hiding cover.
• Nests are bulky structures of coarse twigs, bark strips and plant stems lined with fine grasses, horse hair and fine rootlets.

Reproduction

• Can arrive in British Columbia as early as April or May, but there is often a second influx in mid-June; males select suitable sagebrush stands where they sing from the tops of tall shrubs to attract females.
• Nesting starts from late May to late June.
• Females lay 4 or 5 eggs which are incubated by both parents for about 15 days; eggs hatch from early June to late July; young seen from mid-June to mid-August.
• Migrate south in late August or early September.

Food Habits

• Thrashers are omnivorous, eating mainly insects and berries.

Interesting Facts

• The Sage Thrasher nests almost exclusively in mature big sagebrush environments.
• Sage Thrashers are known to build shade canopies from sagebrush twigs over nests.
• The genus Oreoscoptes means "mimic of the mountains" and refers to the Sage Thrasher's song.
• Birds prefer running to flying when searching for food.

References

1. Blood, D.A. 1995. Sage Thrasher; Wildlife at Risk in British Columbia. Brochure. Ministry of Water, Land and Air Protection, Victoria, British Columbia
2. Cannings, R.J. 1995. Status of the Sage Thrasher in British Columbia. Wildlife Branch, Ministry of Water, Land and Air Protection Lands and Parks, Victoria, British Columbia
3. Campbell, R.W., N.K. Dawe, I. McTaggart-Cowan, J. Cooper, G. Kaiser and M.C. McNall. 1997. Birds of British Columbia: Volume 3. University of British Columbia Press, Vancouver, BC.
4. Cannings, R.A., R.J. Cannings and S.G. Cannings. 1987. Birds of the Okanagan Valley, British Columbia. Royal British Columbia Museum, Victoria, BC.