The White-rumped Shrikes 
No. 120 
White-rumped Shrike 
No. 120a White-rumped Shrike 
A. 0. U. 622a. Lanius ludovicianus excubitorides Swainson. 
Description. — Adult male: Dark bluish gray above, changing abruptly to 
white on upper tail-coverts; scapulars chiefly white; wings chiefly black, the edges 
white, a small white patch at base of primaries, and the inner quills narrowly tipped 
with white; tail black, the outer pair of feathers chiefly white, the succeeding broadly 
tipped with white in descending ratio until color disappears in two central pairs; below 
white, slightly soiled, or buffy-tinted, on breast and sides, but everywhere strongly 
contrasting with upperparts; a narrow frontal line, nasal tufts, lores, and ear-coverts, 
black—continuous and passing mostly below eye. Bill and feet black. Adult female: 
Similar to adult male, but somewhat duller; the gray of upperparts faintly washed with 
olivaceous; the buffy of underparts deeper, more sordid, with some showing of darker 
vermiculation. Immature males of the second year are also glossed with olivaceous and 
retain vermiculation below. Young of the year: Colors of adult, less strongly con¬ 
trasted; lower parts washed with brownish; loral bar obscure; more or less vermiculated 
with dusky all over (in younger birds), or upon the underparts alone (save throat and 
crissum, which are immaculate); ends of wing-quills, coverts, and tail-feathers often 
with ochraceous or rusty markings. Length of adult male about 215.9 (8.50); wing 
100.6 (3.96); tail 99 (3.90); bill 15.3 (.60); tarsus 28 (1.10). 
Recognition Marks. —Towhee size or larger; dark gray above; whitish below; 
longitudinal black patch of head; wings black and white; breast of adult unmarked, as 
distinguished from both L. borealis invictus and L. 1 . gambeli. 
Nesting. — Nest: A bulky but well-built structure of sticks, thorn-twigs, sage- 
bark, dried leaves, etc.; heavily lined with wool, hair, and feathers; placed at moderate 
heights in bushes or trees. Eggs: 5 to 7; dull grayish or greenish white, thickly speckled 
and spotted with grayish olive or buffy brown. Av. size, 24.6 x 18.5 (.97 x .73). 
Season: April, June; two broods. 
Range of Lanius ludovicianus. —North America from southern Canadian prov¬ 
inces south to southern Mexico. 
Range of l. I. excubitorides. —Western North America from the Great Plains 
westward, except Pacific Coast district, and from Manitoba and the plains of Sas¬ 
katchewan south over the tablelands of Mexico; south in winter over the whole of 
Mexico, intergrading with L. 1 . migrans in region of the Great Lakes. 
Distribution in California. —Common resident east of the desert and Sierran 
divides—exact area of intergradation with succeeding form indeterminable, but lies 
west of the Sierras. 
Authorities.—Baird ( Collyrio excubitorides) , Rep. Pac. R. R. Surv., vol. ix., 
1858, p. 327, part (spec, listed from Fort Yuma); Cones, Birds Col. Val., 1878, pp. 535, 
561 (syn., habits, hist., nomencl., etc.); Judd, U. S. Dept. Agric., Biol. Surv. Bull., 
no. 9, 1898, p. 20, part (food); Swarth, Pac. Coast Avifauna, no. 4, 1904, p. 48 
(s. Ariz.; habits, nesting dates, molt); Grinnell, Univ. Calif. Pub. Zook, vol. xii., 1914, 
p. 188 (Colo. Valley; crit.; habits, etc.). 
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