Clay Colored Sparrow

Maximum longevity: 6.9 years (wild)

Spizella pallida (Swainson)

This sparrow was previously known (Friedmann, 1963:163) to be parasitized by the brown-headed cowbird frequently in Alberta, but there were only scattered records from elsewhere, e.g., only 1 such case from North Dakota. Now there is evidence that this sparrow is frequently imposed upon in that state. Dr. R. E. Stewart informs us that he has data on 14 North Dakota instances of parasitism, including the 1 referred to above. The 13 additional cases represent 39.4 percent of 33 active nests examined, a high rate of parasitism, a rate exceeded in North Dakota only by the yellow warbler (44 percent) in Dr. Stewart's state files. In the files of the Prairie Nest Records Scheme are 65 instances of cowbird parasitism on this sparrow in Alberta, Saskatchewan, and Manitoba. In these prairie provinces the clay-colored sparrow is a very common victim, second in frequency only to Brewer's blackbird. The 65 Prairie records more than equal in number all the records from the entire range of the sparrow known a decade earlier. These 65 records constitute 23.6 percent of a total of 275 clay-colored sparrow nests reported to the Scheme up to mid-1975. In Ontario, 3 nests out of 13 reported to the Toronto files were parasitized. What degree of biological success for the cowbird is involved in this excessive host selection is, however, uncertain, in view of Salt's (1966) conclusion that in his area of Alberta the clay-colored sparrow did not tolerate, or, at least, did not incubate, the eggs of the parasite. Salt's conclusion needs to be corroborated by experiments as he does not state how many parasitized nests served as the basis for his statement, and the intolerance he noted consisted largely of nest desertion. Inasmuch as birds may desert their nests for various reasons, the mere fact of desertion cannot be rigidly connected with cowbird parasitism however much the two may seem to have a cause-and-effect relationship.

BREWER'S SPARROW

The clay-colored sparrow or clay-coloured sparrow (Spizella pallida) is a small New World sparrow of North America.

Adults have light brown upperparts and pale underparts, with darker streaks on the back. They have a pale crown stripe on a dark brown crown, a white line over the eyes, a dark line through the eyes, a light brown cheek patch and brown wings with wing bars. The short bill is pale with a dark tip and the back of the neck is grey; they have a long tail. Non-breeding adults and immature resemble chipping sparrows and Brewer's sparrows; they often form flocks with these birds outside the nesting season.

Their breeding habitat is shrubby open areas and jack pine woods across central Canada and central northern United States east to the Great Lakes, and is expanding further eastward. The nest is an open cup on the ground or low in a shrub.

These birds migrate in flocks to southern Texas and Mexico.

They forage on the ground, mainly eating seeds and insects. Outside the nesting season, they often feed in small flocks. While nesting, these birds may feed far from the nest; feeding areas are not defended.

The male sings from an open perch to indicate his ownership of the nesting territory. The song is a Bzzzz bzzzz za za.

This bird's nests are made of grasses and lined with fine materials or hair. Three to five splotched blue-green eggs are laid and incubated for 11 days. They are often parasitized by the brown-headed cowbird; the nest may be abandoned when this happens.

South Padre Island - Texas