14 NORTH AMERIC.VN BIRDS. 



tlie I^fackeiizie Eiver ami the (Vjppenniiie, more than 200 specimens 

 (mostly with their ej^^gs) having been sent thence to the Smitlisonian 

 Institution hy Mr. MacFarlane. In all this number there was not a 

 single bird that had any approach to the characters of 1\ swainsoni, as 

 just given. From the Slave Lake region, on the other hand, T. swainsoni 

 was received in nearly the same abundance, and unmixed during the 

 breeding season with T. alicia'. 



Turdus swainsoni, Cabams. 



OLIVE-BACKED THBUSH; SWADTSOH'S THBUSH. 



Turdus swainsoni. Cab. Tschudi, Fauna Peruana, 1844-40, 188. — ^Sclateh & Salvin, 

 Ibis, 1859, (! (Guatemala). —ScLATEii, P. Z. S. 1858, 451 (Kcuador) ; 185y, 326.— 

 In. Catal. 1861, 2, no. 11. — lUiiiD, Birds X. Am. 1858, 216; Rev. Am. B., 1864, 19. 

 — (JrNDL.vcii, Cab. Jour. 1861, 324 (Cuba). — Ib. Kei>ert. 1865, 229. — Pelzkln, Om. 

 Brazil, ii. 1868, 92 (Marambitanas, Feb. and March). — Lawk. X. Y. Lye, IX, 91 

 (Costa Riea). — Kidgway. — Maynaud. — Samuels, 152. — Cooper, Birds Cal. 6. — 

 Dall k Baxxisteu. Turdus minor, (Imelix, Syst. Xat. I, 1788, 809 (in part). 

 Turdus olivaceus, Gikauh, Birds L. Island, 1843-44, 92 (not of Lixx.). (/) Turdus 

 minimus, Lafresx.\ye, Rev. Zoiil. 1848, 5. — Sclater, P. Z. S. 1854, 111. — Bryaxt, 

 Pr. Best. See. VII, 1860, 226 (l3ogota). — Lawrexce, Ann. X. Y. Lye. 1863. (Birils 

 Panama, IV, no. 384.) 



Sp. Char. Upper parts unilbrm olivaceous, with a decided shade of fjreen. The fore 

 part of breast, the throat and chin, pale brownish-yellow ; rest of lower parts white ; 

 the sides washed with brownish-olive. Sides of the throat and fore part of the breast 

 with sub-rounded spots of well-defined brown, darker than the back ; the rest of the 

 breast (except medially) with rather less distinct spots that are more olivaceous. Tibiie 

 yellowish-brown. Broad ring round the aye, loral region, and a general tinge on the 

 side of the head, clear reddish buff. Length, 7.00 ; wing. 4.1.3 ; tail, 3.10 ; tarsus, LIO. 



Hab. Eastern North America ; westward to Humboldt Mountain an<l Upper Columbia; 

 perhaps occasionally straggling .as far as California; north to Slave Lake and Fort Yukon ; 

 south to Ecuador and Brazil. Cuba, Guxdlacii ; Costa Rica, Lawr. 



Sjiecimens examined from the northern regions (Great Slave Lake, Mac- 

 kenzie Kiver, and Yukon) to Ouatemala; from Atlantic States to East 

 Humboldt IMountains, X^>^vada, and from intervening localities. Tlie ex- 

 tremes of variation are the hrov:nish-6\i\Q of eastern and the clear darl- 

 greenish-olive of remote western specimens. There is no observable dif- 

 ference between a Guatemalan skin and one from Fort Bridger, Utah. 



Habits. The Olive-backed Thrush, or " Swamp Kobin," has very nearly 

 the same habitat during the breeding season as that of the kindred species 

 with which it was so long confounded. Although Wilson seems to have 

 found the nest and eggs among the high lands of Xorthern Georgia, it is yet 

 a somewhat more northern species. It does not breed so far south as 

 Massachusetts, or if so, the cases must l)e exceptional and very rare, nor 

 even in Western Maine, where the "Ground Swamp Robin" {T. pailasi) is 

 quite abundant. It only becomes common in the neighborhood of Calais. 



