LAND BIRDS. 715 



1893. These records are all based on specimens forwarded by the hght 

 keepers and identified by the Division of Biological Survey, Washington, 

 D. C. It was found on Isle Royale as a migrant only in 1905, on September 

 5, and again Septeml;)er 12 and later. Norman A. Wood found it abundant 

 on the Charity Islands, Saginaw Bay, September 14 to October 10, 1910. 

 It is by no means rare about the College (Ingham Co.), where specimens 

 are taken almost every May and September. 



According to Bicknell "the song of the Gray-cheeked Thrush commences 

 low and reaches its loudest, and I think its highest, part a little beyond 

 half its continuance. It is throughout much fainter and of less forcible 

 delivery than the song of the Olive-backed species" (Auk, I, 1884, 130). 



The nest and eggs of the Gray-cheeked Thrush (not likely to be found 

 in Michigan) are not distinguishable with certainty from those of the 

 Olive-back. The nest is placed in low bushes or trees (rarely on the ground) , 

 and the eggs are greenish-blue, spotted with rusty brown, and average 

 .92 by .67 inches. The ground color is said to be of a decidedly deeper 

 blue than in the Olive-back. 



TECHNICAL DESCRIPTION. 



Allah: tapper parts unifunn olive-broAvn from top of head to ti]) of tail; sides of head 

 grayish, and without any well marked eye-ring; throat and belly white, the former often 

 tinged with biiff; sides of throat and entire breast with arrow-shaped spots of brown 

 and black. Sexes alike in size and color. 



Length 7 to 7.75 inches; wing 3.7o to 4.40; tail 2.9.5 to 3.40. 



322. Olive-backed Thrush. Hylocichla ustulata swainsonii {Tschadi). 



(758a) 



Synonyms: Swainson's Thrush, Swamp Robin. — Turdus swainsoni, Tschudi, 1X45 

 and most authors vmtil 1877. — Turdus ustulatus swainsoni, Ridgw., 1877. — Hylocichla 

 ustulata swainsoni, Ridgw., 1880, and most recent authors. 



Entire upper surface clear olive, as in the Graj^-cheeked Thrush, but 

 a distinct buffy eye-ring and the cheeks not gray but buff. The throat 

 and chest are also much more buffy than in the Graj'-cheeked Thrush. 



Distribution. — Eastern North America and westward to the Upper 

 Columbia River and East Humboldt Mountains, straggling to the Pacific 

 coast. Southward in winter to Cuba, Guatemala, Nicaragua, Columbia, 

 Ecuador and Peru. Breeds in the northern Alleghanies, the Cat skills, 

 the mountainous parts of southern New England, southern Sierra Nevada 

 and northward. 



The Olive-backed Thrush is a much more common migrant in IMichigan 

 than the preceding species. It arrives from the south about the first 

 week in May, somewhat earlier in the southern jjart of the state in favoral)lc 

 seas(jns, and much later, even the last week of May, in the I'pper Peninsula. 

 Thrushes ai'e among the Ijirds most frequently killed at lighthouses and 

 there are scores of I'ecords for the present species from the Michigan lights. 

 Tlie earliest spring record is from Spectacle Reef Light, May 10, 1888, and 

 the only record from Detroit River Light is May 15, 1886. The numerous 

 spring records from Spectacle Reef are mostly included between IMay 20 

 and .Tune 1, but there is a single record of j\hiy 17, 1885, and one of June 

 2, 1889. Fall records from the same Light range from September 9, 

 1894 to October 20 of the same year, but the majority of records fall l)e- 

 tween September 20 and October 10. The records at Big Sable Light, 



