BELL SPARROW. Amphispiza belli (Cassin)

Field characters.—Size of Junco or Linnet; tail as long as body. Upper surface plain dull brown, becoming iron gray on head; area in front of eye, and conspicuous stripe down side of neck from bill, black (pl. 8i); spot on each side of brow, lower cheek, and throat and under surface of body, white; a distinct black spot on center of breast. Voice: Song of male a set utterance of tinkling quality, tweesitity-slip, tweesitity-slip, swer; also a faint one-syllabled call note, seet.

Occurrence.—Common resident in Upper Sonoran Zone over western base of Sierras. Lives almost exclusively in greasewood chaparral. Observed by us at Pleasant Valley, near Coulterville, and near El Portal. To be seen in pairs or scattered family parties.

The Bell Sparrow is closely associated with that type of chaparral, made up almost purely of the greasewood, which clothes so much of the dry foothill country flanking the west base of the Sierra Nevada. Since this is a bird of dull colors and retiring habits, it will not likely be seen by a person passing quickly along any of the dusty roadways through this 'chamisal.' The bird student interested in forming an acquaintance with this sparrow will need to tarry at some place in the foothills and spend a few hours amid the greasewood itself.

In 1914 and 1915 we saw but little of the Bell Sparrow, and that only incidentally, as we were endeavoring to get a general idea of the fauna in the vicinity of El Portal and Pleasant Valley; but in 1919 some time was spent at Blacks Creek, west of Coulterville, in seeking a special acquaintance with this species. To do this we left the beaten roadway and grassy clearings and pushed our way up onto the slopes covered solidly with greasewood. Here we followed a growth of young bushes which had sprung up where once a narrow clearing had been made for miles across the country beneath a power line. Our field notes of this day, May 12, 1919, are substantially as follows.

The hillside was a dry, south-facing one, of slaty formation covered with a typical California chaparral composed of greasewood (Adenostoma fasciculatum) with scattering bushes of wedge-leafed ceanothus (Ceanothus cuneatus) and manzanita (Arctostaphylos mariposa). Here a Bell Sparrow was found, its headquarters proving to be on a subsidiary ridge running down into an oak lined ravine. We located the bird first by hearing from a distance its tinkling song. This may be variously written, inksely-inksely-inksely-ser, or tweesitity-slip, tweesitity-slip, swer, or sweesely-swer, sweesely-swer, swer, according to different attempts at transcription. The rhythm of this utterance was notable. The bird sang every 9 or 10 seconds, each song lasting about 2-1/2 seconds. The song would be repeated for several minutes from one perch and then the bird would change to another location. It would perch on the topmost shoot of a greasewood bush, facing away from the wind, its feathers blown outward somewhat, and would rock back and forth in keeping its balance on the swaying twig. This individual bird seemed to be centering his attentions on some particular portion of the hillslope, for he circled about within a radius of not over 150 feet, singing from one perch, then changing to another. Between song periods he would disappear, presumably to forage, within the mantle of brush, where also probably was his mate, though she kept well out of our sight.

Searching around amid the smaller greasewood bushes on the one-time clearing, we found 8 old nests belonging undoubtedly to this species. These ranged from 6 to 30 inches above the ground, but most of them were not more than 10 inches up. All were in small greasewood bushes, not over 24 inches tall, and placed within the cluster of upright stems. The nests were composed of small twigs of the greasewood, with the dry whitish stems of some annual plant as a felting for the interior. A typical weathered nest measured approximately 3 inches in outside diameter. So large a number of nests found in the one area (not over 150 feet in diameter) would suggest continued occupancy of the little tract of an acre or so for a number of years by this one pair of birds or their ancestors.

No other bird of any species was encountered during our stay in this area of an acre or more. It would seem that the Bell Sparrow, at least at nesting time, closely restricts itself to a type of territory such as is not sought out by other birds; it is not consequently bothered by competition.

Moving on to the next little hillslope we observed another singing male Bell Sparrow; a careful examination of the many hillsides in the basin of Blacks Creek would probably have revealed a pair of Bell Sparrows on each one. Hence, while the number of Bell Sparrows to be found in any one limited area is small, the total population in the entire greasewood belt of the western foothills must be large. As already stated, not one of these birds is likely to come to the attention even of the careful bird student save as he or she makes particular effort to find the species.