Species: Oreoscoptes montanus
Sage Thrasher
Species
Encyclopedia of Puget Sound
Classification
Kingdom
Animalia
Phylum
Craniata
Class
Aves
Order
Passeriformes
Family
Mimidae
Genus
Oreoscoptes
NatureServe
Classification
Other Global Common Names
Cuitlacoche de ChÃas - moqueur des armoises
Informal Taxonomy
<p>Animals, Vertebrates - Birds - Perching Birds</p>
Formal Taxonomy
Animalia - Craniata - Aves - Passeriformes - Mimidae - Oreoscoptes - Placed in Sturnidae in Sibley and Ahlquist (1984).
Ecology and Life History
Short General Description
Medium-sized songbird, 20-23 cm long with a wingspan of 32 cm (Reynolds et al. 1999). Males and females brownish gray on the back with indistinct streaking, especially on the crown. Whitish underside with dark streaking. Outer tail feathers tipped white, wings with thin, white wingbars.
Migration
<p>false - false - true - Departs from northern breeding areas by end of September, returns in April, May, or June.</p>
Non-migrant
false
Locally Migrant
false
Food Comments
Feeds on a wide variety of insects, including grasshoppers, beetles, weevils, ants, bees, etc. Also feeds on fruits and berries.
Reproduction Comments
Clutch size four to seven (usually three to five). Incubation about 15 days, by both sexes. Nestlings altricial and downy. Nestling period about 13 days. Probably can raise two broods per season, but probably only one brood per year in British Columbia (Cannings 1992). In Oregon, reproductive parameters were not associated with climatic variation (Rotenberry and Wiens 1989).
Ecology Comments
Density rarely exceeds 30 per square kilometer (Rotenberry and Wiens 1989). In eastern Washington sagebrush shrub-steppe, mean densities reported at 0.09 to 0.2 individuals per hectare (Dobler et al 1996). Breeding density 0.05 individuals per hectare or less in shadscale habitat in eastern Nevada (Medin 1990). Territory size in eastern Idaho averaged 8 territories per 1.86 hectares in one year, 11 territories per 1.14 hectares the following (Reynolds 1981). <br><br>Relative abundance significantly positively correlated with the following species in western U.S., based on North American Breeding Bird Survey data (T.D. Rich, unpubl. data): Brewer's Sparrow (SPIZELLA BREWERI; r = 0.87, P < 0.001), Sage Sparrow (AMPHISPIZA BELLI; r = 0.73, P < 0.001), Gray Flycatcher (EMPIDONAX WRIGHTII; r = 0.73, P P < 0.001), Sage Grouse (CENTROCERCUS UROPHASIANUS; r = 0.71, P < 0.001), Rock Wren (SALPINCTES OBSOLETUS; r = 0.61, P < 0.001), Vesper Sparrow (POOECETES GRAMINEUS; r = 0.53, P < 0.001), Prairie Falcon (FALCO MEXICANUS; r = 0.53, P < 0.001), and Green-tailed Towhee (PIPILO CHLORURUS; r = 0.51, P < 0.001).
Length
22
Weight
46
Conservation Status
NatureServe Global Status Rank
G5
Global Status Last Reviewed
1996-12-03
Global Status Last Changed
1996-12-03
Distribution
Conservation Status Map
<img src="http://www.natureserve.org/explorer/servlet/GetMapGif?CA.BC=S1&CA.SK=S1&US.AZ=S5&US.CA=SNR&US.CO=S5&US.ID=S3&US.KS=__&US.MT=S3&US.NN=S3&US.NE=SH&US.NV=S5&US.NM=S3&US.OR=S4&US.SD=S2&US.TX=__&US.UT=S4&US.WA=S3&US.WY=S5" alt="Conservation Status Map" style="width: 475px; height: auto;" />
Global Range
BREEDING: southern British Columbia, central Idaho, and south-central Montana south through the Great Basin to eastern California, northeastern Arizona, and west-central and northern New Mexico (AOU 1983, Reynolds et al. 1999). Breeds at least irregularly in southern Alberta and southern Saskatchewan (Cannings 1992). NON-BREEDING: central California, southern Nevada, central Arizona, central New Mexico, and central Texas south to southern Baja California, northern Sonora, Chihuahua, Durango, Guanajuato, northern Nuevo Leon, and northern Tamaulipas (AOU 1983, Reynolds et al. 1999).