The White-breasted Nuthatches 
feet. The nest is composed typically of interlaced oak blossoms, felted 
with down from the oak leaves, and lined copiously with feathers. Both 
sexes assist in nest-building, and the mated birds hunt together for 
suitable material, to a distance of several hundred yards. The birds 
display considerable anxiety whenever the nest is approached, and are 
very likely to betray the presence of an otherwise inconspicuous home. 
Unlike other titmice, however, the female is seldom caught at her task 
of incubation. 
As is the case with northern members of this genus, even P. m. 
saturatus of Puget Sound, plumbeus starts building in March or early 
April, and in many assured instances nests again in late May, June, 
or even July. A special accommodation to southern climate may be 
noted in the custom which the birds observe of breaking a hole through 
the fabric of the nest-wall, at a level with the floor, as soon as their babies 
are half-way grown. That this is actually for ventilation only is assured 
by the fact that the parents continue to go and come by the established 
entrance overhead. One cannot help wondering whether these birds 
close the window at night. 
No. 128 
White-breasted Nuthatch 
No. 128a Slender-billed Nuthatch 
A. O. U. No. 727a. Sitta carolinensis aculeata Cassin. 
Description. —Adult male: Top of head, nape, and upper boundary of back 
shining black, with a slight greenish reflection; remaining upperparts ashy blue (clear 
green-blue-gray to clear Payne’s gray); outer wing-quills fuscous, the second and 
three or four succeeding primaries narrowly touched with white on outer web in retreat¬ 
ing order; inner quills and coverts edged narrowly with blue-gray or whitish; tail- 
feathers, except upper pair, black, the outer pairs squarely blotched with white in 
subterminal to terminal order; sides of head, and neck well up including eye, and under¬ 
parts, white with a faint bluish tinge; distinctly marked, or washed more or less, on 
flanks and crissum with rusty brown. Bill stout, subulate, the under mandible slightly 
recurved, blackish plumbeous above, lighter at base of lower mandible; feet dark brown; 
iris brown. Adult female: Similar to male, but black of head and back more or less 
veiled by color of back. Length 139.7-154.9 (5.50-6.10); wing 87 (3.43); tail 46 (1.81); 
bill 19.5 (.77); tarsus 18.2 (.72). 
Recognition Marks. —Warbler to sparrow size; tree-creeping habits; black 
and ashy blue above; white below. 
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