726. Brown Creeper. Certhia familiaris americana.

Range.--Eastern North America, breeding from the northern tier of states northward; winters in the United States.

These peculiar, weak-voiced Creepers are common in northern United States during the winter, when they may be seen slowly toiling up the tree trunks, searching the crannies of the bark for larvae. They make their nests behind loose hanging bark on old tree stubs, usually at low elevations, building them of twigs, bark, moss, etc., held together with cobwebs. The eggs, which are laid in May or June, are pure white, specked and spotted with reddish brown; they average in size .58 × .48. The nests are most often found under the loosened bark on coniferous trees.

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726a. Mexican Creeper. Certhia familiaris albescens.

Range.--Western Mexico north to southern Arizona.

The nesting habits of this brighter colored form are the same as those of the others.

726b. Rocky Mountain Creeper. Certhia familiaris montana.

Range.--Rocky Mountains, breeding from New Mexico to Alaska.

The eggs of this grayer variety cannot be distinguished from those of the eastern birds and the nests are in similar situations.

726c. California Creeper. Certhia familiaris occidentalis.

Range.--Pacific coast from southern California north to Alaska.

An abundant species, especially on mountain ranges, breeding behind the bark chiefly on pine trees. The eggs are not different from those of the others.

726d. Sierra Creeper. Certhia familiaris zelotes.

Range.--Sierra Nevada Mountains in California and the Cascade Range in Oregon.

Very similar to the last and with the same habits; eggs indistinguishable.