THE OLIVE-BACKED THRUSH. 235 



named ])laces. nests might Ix' set against the trunk un a huri/jintal hnil), hnl 

 were more often at some distance from it. The birds were very sensitive 

 aiiont molestation l)efore eggs were laid, and would desert a nest in process 

 of construction on the merest suspicion that a stranger had looked into it. 

 Alter deposition, howe\er, the mother Thrush was found to be verv devoted 

 to her charges, and great confidence was often engendered by carefulK' con- 

 sidered advances. 



At Glacier, nest-building axerageil to commence about the j^th of .May. 

 and the (h'sl eggs were found on the 1st of June. The last set was fomid July 

 i^tli. .\I1 nests e.xamined in the earlier part of the season contained four 

 eggs: those found later, ])resuniabiy second efforts. ne\er had more than tiiree. 



As a curious example of the use of the imagination on the ])art of early 

 writers, take this from our \enerated Cooper": "The eggs, unlike those of 

 most thrushes, are white, s]x)tted thickly witli brown, and four or li\e in 

 number." The brown si)otting is all right and an unpigmented shell is not an 

 impossibility, but de\'iations from the characteristic greenish blue of the 

 ground-color have not since been re[)orted. 



No. 94. 



OLIVE-BACKED THRUSH. 



.\. ( ). L'. Xo. 758a. Hylocichia ustiilala swainsonii (Cab.). 



Synonyms. — Sw.mxson's Thrush. Eastkrx Oli\'i:-back. Ai.ma's 

 Thrisii (H. It. aliiuc Obcrh., disallowed by .\. O. U. Com.). 



Description. — .Idiilts: Similar to //. ustiilata but grayer and more olivace- 

 ous; "color of upperparts varying from olive to grayish hair brow-n in summer, 

 from deep olive to slightly brownish olive in winter" : ground color of underparts 

 lighter huffy (yellowish buff' or creamy buff) : sides and flanks grayish — instead 

 of brownish-olive. Size of last. 



Recognition Marks. — .\s in jireceding: grayer above, lighter bulTy lielow. 



Nesting. — Xcst and /:'(/;/.'; indistinguishaljle from those of typical form, //. 

 itstiilata. 



General Range. — North .\nierica in general cxce])t Pacific coast district 

 south of Cross Sound and Lynn Canal ; breeding from the mountainous districts 

 of the United States ("especially nortlierly) north to limit of trees: soiuh in wiiUer 

 tlinioiU Mexico and Central .\iuerica to I'eru, Bolivia, etc. * 



Range in Wasliington. — Imperfectly made out as regards that of If. 

 n.<itithita. Found breeding in the valley of the Stehekin hence presumably summer 

 resident in timbered districts of eastern Washington. 



Authorities. — Bowles and Dawson, Auk. \'ol. XX\'. ( )ct. ii)o8. p. 48^;. 



Specimens. — I'rov. 1'.. 



a. Ri-p. Pac. R. K. Snrv., Vol, Nil., Book II.. i860, p. 171. 



