SAGE THRASHER. Oreoscoptes montanus (Townsend)

Field characters.—Size nearly that of Robin; build more slender. Under surface of body dull white marked with coarse streaks of brown; upper surface plain grayish brown; tail tipped with white. Voice: Song a series of clear warbling notes of varying pitch, well sustained to the end.

Occurrence.—Common summer visitant east of Sierra Nevada, from near Silver Lake eastward. Recorded once (April 20, 1919) as a transient on west slope at Smith Creek, east of Coulterville. Keeps close to ground; lives in sagebrush during summer season. Solitary or in pairs.

The Sage Thrasher is to be found in the true sagebrush (Artemisia tridentata) which abounds on the flats and gentler slopes east of the main Sierra Nevada. The bird's spotted under surface and plain back both match in color tone the prevailing gray of its environment.

Sage Thrashers visit the Mono region only in summer, spending the winter months on the lower deserts to the south. The species was first recorded in 1916 on May 6, one bird being taken near Williams Butte on that date. In 1915 the birds were still in the region in considerable numbers as late as September 20. Censuses during the third week of September, 1915, yielded 2 to 6 of these thrashers per hour of travel within the sage-covered areas, but this included many young-of-the-year. Counts at nesting time would have revealed a smaller number. The birds perch for singing, or for a survey of the vicinity, on the tips of bushes. They are quick to take alarm, and drop to the ground, scudding away on foot until they have so much of the brushland between themselves and their pursuer that they are entirely lost to view.