Grasshopper Sparrow, Ammodramus savannarum
Grasshopper Sparrows gets their name from their song, an insect-like buzz. They are
quite secretive except when they sing, usually early on a spring morning, from a plant
stalk in a grassy area. The birds above and the two below were singing on the same
hillside in Ed Levin Park in the foothills of the Diablo Range in eastern Santa Clara County.
The bird at the top and one below are in fresh plumage in April and March respectively, while the one above, seen in June, has more of the subtle colors of its breeding plumage worn off.
The fresh-plumaged bird about showed erected crown feathers, the only time I've seen this on a Grasshopper Sparrow.
The picture above was taken on the first occasion I ever saw a pair of Grasshopper Sparrows together.
The flat head, large bill, buffy face, and dark spot at the rear of the auriculars
all are marks for the species; the dark striping on the upper breast and the more
subdued colors indicate that it is a juvenile.