California Thrasher, Toxostoma redivivus

California Thrasher
California Thrashers, with their spectacularly long curved bills,  are permanent residents of coastal and foothill habitat in California, particularly in or near chaparral. They are also less commonly found in suburban parks and gardens that have plenty of low cover; we have them regularly in the residential part of the Stanford campus, which borders on the Santa Cruz Mountain foothills.

California Thrasher
Thrashers sing all year around, but particularly in the Spring and then with almost
equal vigor in Fall, starting around the autumnal equinox; the bird shown above is
singing in November. The phenomenon of "autumnal recrudescence" is found
in some bird species, notably including thrashers; when Fall days are roughly as
long as the days of the Spring mating season, birds experience a hormonal surge which
triggers singing by males, despite the fact that they will not be breeding for many
months. California Thrashers form permanent pairs, which occupy the same
territories for the whole year, so this "out of season" singing may serve
pair-bonding and territory-defense functions particularly useful to them. 

California Thrasher
When not singing, the California Thrasher is pretty inconspicuous, though not as difficult to find as some of the desert thrashers. As described by Birds of North America, and as illustrated above, "it feeds chiefly under cover on the ground by swinging its formidable bill in sideways arcs, digging vigorously and noisily in leaf litter ('thrashing' -- hence the name) and peering intently into its excavations."

California Thrashers
We have had California Thrashers nest in our yard; above, a parent feeds a begging fledgling right under our backyard deck.

California Thrashers
As already noted, California Thrashers are sedentary, strongly territorial, and form long-term pair bonds; Birds of North America reports that "Territory [is] established and defended by both members of pair; territory borders often disputed with neighbors. Fighting [is] occasionally observed, when disputants scrabble with each other vigorously on ground, wings beating, sometimes rising interlocked into air with legs and bills thrusting." The pictures above and below show such a battle, in October, when males were singing on territory and apparently generally feeling their Fall hormonal surge; I learned first hand that those long curved bills can be put to uses other than excavating among dead leaves. More pictures of this battle can be seen here.

California Thrashers