Sage Thrashers are the smallest thrashers in North America. They live in the West’s vast sagebrush steppe.
Sage Thrashers are small thrashers with a short, strait bill and pale yellow eyes. They have heavily streaked underparts with a grayish brown back and two thin white wingbars. Sage Thrashers are thrushlike overall, often standing erect with the wings slightly drooped when perched.
These fairly small thrashers are robin-sized, adults having a length of 7.9-9.1 in (20-23 cm) and a weight of 1.4-1.8 oz (40-50 g). They have a wingspan of 12.6 in (32 cm).
Sage Thrashers occur in arid, open ground dominated by relatively dense sagebrush. They live in the vast West of North America.
Sage Thrashers are short distance migrators, with almost all Sage Thrashers leaving breeding grounds in the Great Basin for wintering grounds in the Desert Southwest and Mexico.
Sage Thrashers feed primarily on terrestrial insects and arthropods, which they often capture while running on the ground amid sage cover. They also forage for berries. During breeding season they forage alone, and occasionally in small groups after breeding.
Sage Thrasher's nests are built on or near ground, usually placed in the tallest big sagebrush (Artemisia tridentata) around, particularly in ones with wider crowns. These thrashers will take as much advantage of overhead cover as they can.
When building the nest, both parents will help. The bulky twig nest is lined with grasses, rootlets, or hair and fur. Externally, the nests measure about 4 inches tall and up to 8 inches long. The cup averages 1.8 inches deep for first nests and 3.2 inches for second nests.
Sage Thrashers will have one to two broods with four to five eggs in each. The eggs are a vibrant turquoise with heavy splotches of chestnut brown. They are 0.9-1.0 in (2.28-2.61 cm) in length and weigh 0.9-1.0 in (2.28-2.61 cm). Incubation peroid for Sage Thrashers are 11-17 days and nestinf period is 8-14 days. After the eggs hatch, the nestlings have translucent reddish-orange skin, turning grayish yellow with time, and are covered with tracts of blackish down within a few days.
Sage Thrashers become especially shy during breeding, and prefer running secretively, rather than taking flight. However, during territory establishment, male Sage Thrashers sing while performing circular, undulating flights through the sagebrush, often sweeping low among the vegetation. Upon landing, and during song, they raise and flutter both wings in a display called the bilateral wing display. Like most songbird species, their songs help them both attract mates and to define territory boundaries. Males often sing back and forth with a neighbor on the border between their two territories.
Adults Sage Thrashers are extremely secretive around their nests, and when returning to the nest, they will typically fly to within about 30 feet of the nest and then sneak the rest of the way on foot. Both parents contribute equally in incubating eggs, feeding, and brooding the young. Both parents also remove eggshells and fecies from the nest.
During migration and the nonbreeding season, Sage Thrashers can form impressive flocks numbering in hundreds, suggesting they are social away from breeding territories.
Males have long, complex, melodic songs, with remarkable variety. The rambling series of phrases, often followed by soft clucking notes, is continuous and scattered with moments of repetition and mimicry. Their songs can be very long indeed; one male was recorded singing for 22 minutes straight.
When alarmed, their call is a low, hoarse cluck, very similar to a Red-winged Blackbird, accompanied by a flick of the tail. They occasionally give a descending, clear, two-noted whistle, and a variety of scolding calls.
Sage Thrashers are numerous but their populations are declining due to loss of appropriate habitat. Compared to most sagebrush-dependent birds though, so far, they are faring well in the face of development. Their conservation concern is low.
- Due to their ability to mimic other birds, their early name was “mountain mockingbird."
- Sage Thrashers are also called Cuitlacoche de Las Artemisas (in Spanish) and Moqueur des armoises (in French).