THE OLIVE-BACKED THRUSH. 235 
named places, nests might be set against the trunk on a horizontal limb, but 
were more often at some distance from it. ‘The birds were very sensitive 
about molestation before eggs were laid, and would desert a nest in process 
of construction on the merest suspicion that a stranger had looked into it. 
After deposition, however, the mother Thrush was found to be very devoted 
to her charges, and great confidence was often engendered by carefully con- 
sidered advances. 
At Glacier, nest-building averaged to commence about the 25th of May, 
and the first eggs were found on the rst of June. The last set was found July 
15th. All nests examined in the earlier part of the season contained four 
eggs; those found later, presumably second efforts, never had more than three. 
As a curious example of the use of the imagination on the part of early 
writers, take this from our venerated Cooper*: “The eggs, unlike those of 
most thrushes, are white, spotted thickly with brown, and four or five in 
number.” ‘The brown spotting is all right and an unpigmented shell is not an 
impossibility, but deviations from the characteristic greenish blue of the 
ground-color have not since been reported. 
No. 94. 
OLIVE-BACKED THRUSH. 
A. O. U. No. 758 a. Hylocichla ustulata swainsonii (Cab.). 
Synonyms.—Swatnson’s THRusH. EAsTERN  OLIVE-BACK. ALMA’S 
TurusH (H. uw. alme Oberh., disallowed by A. O. U. Com.). 
Description—4dults: Similar to H. ustulata but grayer and more olivace- 
ous; “color of upperparts varying from olive to grayish hair brown in summer, 
from deep olive to slightly brownish olive in winter”; ground color of underparts 
lighter buffy (yellowish buff or creamy buff); sides and flanks grayish—ainstead 
of brownish-olive. Size of last. 
Recognition Marks.—As in preceding; grayer above, lighter buffy below. 
Nesting.—Nest and Eggs indistinguishable from those of typical form, H. 
ustulata. 
General Range.—North America in general except Pacific coast district 
south of Cross Sound and Lynn Canal; breeding from the mountainous districts 
of the United States (especially northerly) north to limit of trees; south in winter 
thruout Mexico and Central America to Peru, Bolivia, etc. 
Range in Washington.—Imperfectly made out as regards that of H. 
ustulata. Found breeding in the valley of the Stehekin hence presumably summer 
resident in timbered districts of eastern Washington. 
Authorities.—Bowles and Dawson, Auk, Vol. XXV. Oct. 1908, p. 483. 
Specimens.—Prov. B. 
a. Rep. Pac. R. R. Surv., Vol. XII., Book II., 1860, p. 171. 
