Wednesday, April 6, 2016

Brewer's Sparrows in San Diego

The Brewer's Sparrow would not win any beauty contest. And, as far as field marks go, it is unremarkable, if you'll pardon the pun. If pressed, you could try to point out some subtle field marks. It has a weakly striped head with numerous tiny black streaks on the brown crown, pale lores, thin eyering, white submustachial stripe with thin brown borders, thin weak wing bars, and a thin long notched tail. It's a streaky little gray-brown sparrow with no stand-out features--its general lack of field marks being its strongest identification character. It makes its home on the endless sea of equally dull gray-green sage flats in the West.

Oh, but to hear it sing! The male's song is a joyously long series of canary-like bubbling notes and buzzy trills, on different pitches, with birds joining together to sing in the dawn chorus. It is one of the characteristic sounds of the Great Basin sage lands. And, they often sing in winter and on migration.

It was the singing that attracted my attention, coming from the chaparral on Black Canyon Road out of Ramona. A migrant trio of Brewer's Sparrows were in the thicker bushes along the road with several other sparrow species, migrants and residents alike.

Brewer's Sparrow
Brewer's Sparrow in chamise, a common chaparral plant. Ramona, California. March 27, 2016. Greg Gillson.
Several migrant Brewer's Sparrows were reported to eBird away from the Desert in the past couple of weeks, including several near Jamul on March 16 and 17, at least 4 at the San Diego Zoo Safari Park at Escondido on March 17, 1 on the Ramona Grasslands Preserve on March 24, and 4 birds on March 26 at San Elijo Lagoon. Several were reported as singing.

Brewer's Sparrow

Brewer's Sparrows winter commonly in the Anza-Borrego Desert, but are rare elsewhere in the county. They can be found away from the Desert during spring and, especially, fall migration. The first nesting birds in San Diego County were verified in 2001 during the Bird Atlas project, but must be considered very rare breeders, well south of their main breeding range.