Fellow Tweets,

This morning, on a hike into the sagelands north of my home, I watched a
family group of Black-throated Sparrows. The 3+ young were fully fledged
and actively calling and chasing after their parents (presumably begging?).
These birds were in the east-west gulch on the south flanks of the
Rattlesnake Hills (T12N R19E Sec 22), in the same area where I've been
hearing and seeing this species since late June. In July I watched adult
Black-throats in an agitated state, though I did not locate a nest (I
didn't really try, not wanting to prompt abandonment). I also watched a
young bird or two flee from me two weeks ago. I presumed it was a juvenile
Black-throat, but didn't get a good look at the bird. The thought occurred
to me it might be a Lark Sparrow, as the two species seem to coexist in
these sagelands.

So today's observations constitute the first proof of successful breeding
in Yakima County. This is my third encounter with breeding by
Black-throated Sparrows in eastern Washington: I've seen an adult feeding
young at Sentinel Gap south of Vantage and observed a fledged young
(Wahluke Slope Wildlife Area).

The more I encounter Black-throated Sparrows in eastern Washington and
observe the habitat they occupy here, the more I wonder if Euro-settlement
hasn't aided a northward extension of their range. They usually occupy
terrain that range conservationists classify as "degraded," most usually
from excessive grazing by cattle or sheep. Such sites typically have a low
cover of grasses and have also lost much of the cryptogam layer (mosses,
lichens, etc that used to form a crust on top of the soil between grasses
and shrubs through much of the shrub-steppe zone. In a few sites, such as
between Vantage and Priest Rapids Dam, they occupy a nearly grass-less
shrub-steppe, here weathering of the surrounding basaltic ridges and flood
deposits has resulted in a very gravelly lithosol. That type of substrate
may be as or more important to this sparrow as the terrain created by
cattle and sheep, but it is of local occurrence in eastern WA.

If my supposition is correct, the influx of Black-throated Sparrows here
may be analgous to that of the Gray Flycatcher over the past 25 years (in
the lower ponderosa pine zone) in that man through his activities
(selective logging in the case of the flycatcher) has created favorable
habitat and allowed a northward push of both these birds into the inland
Northwest.

Andy Stepniewski
Wapato WA