TURDUS SWAINSONI, OLIVE-BACKED THRUSH. 5 



RiDGW., Pr. Pbila. Acad. 1869, 129.— Dall & Ba^^., Tr. Chic. Acad, i, 1869, 

 275. — Coop., B. Cal. i, 1871, 5. — Lawr., Pr. Bost. Soc. June, 1871 (Tres Marias). 

 Titrdus sivainsoni var. ustulatus, Coues, Key, 1872, 73. 



Eal). — The tyjiical form ranges over nearly the whole of North America ; north to 

 the Arctic Ocean, northwest to Behring's Straits, west to the Columbia, south to Cen- 

 tral America, New Granada, and Ecuador. Cuba. Greenland, Europe, and Siberia (acci- 

 dental). Not observed in Southwestern United States. Breeds from Maine and New 

 Hampshire northward (f from New York, Gregg, Pr. Elmira Acad. 1870). Winters 

 from Florida southward. Yar. aliciw has a nearly coincident range, but on the whole 

 appears somewhat more northerly; south to Costa Eica (r. jfYfot/cu/.s). Var. untulatus 

 inhabits the Pacitic coast, from Siika to Mexico (Tres Marias Islands, Grayaon). 



List of specimens. 



19193 



27 



Wind River.. 



May 28, 1860 



F. V. Havdeu.. 



6.50 



11.50 4.00 



LieutcHant Warren's Expedition. — 4707, month of the Missouri River ; 4710, " Nebraska ;" 

 8818, Black Hills. Var. aliciw: 4708, Upper Missouri ; 4711, Jacques River; 4709,4712, 

 Vermilion River. 



Late information lias greatly extended the known range of this species, 

 and in time the above-mentioned exception of its apparent non-occur- 

 rence in the Southwestern United States will probably be done away 

 with. 



As Mr. Allen has repeatedly contended, the characteristics formerly sup- 

 posed to be specifically distinctive of T. aliciw have proved inconstant and 

 not always tangible. I am now nearly satisfied of the propriety of treat- 

 ing it as a variety, though I entertained the contrary opinion for some 

 years. The evidence best favoring the supposition of its validity lies iii 

 the fact that, while occupying substantially the same range as typical 

 filcainsoni, it generally shows some slight peculiarities; these, however, 

 apparently shade into those of sicainsoni. The fact of intergradation may 

 be proved, however we may account for the discrepancies observed in 

 most cases. I think the solution of the problem may be looked for in 

 the probability that ulicice as a rule consists of more northerly-born indi- 

 viduals ; this would bring the case under some known rules, that might 

 account for its peculiarities of larger size and darker color. 



The relationships of var. ustulafus were long sui)posed to be with/?<s- 

 cescens, which is by no means the case. The clew to its true interpreta- 

 tion was found in the discovery that the eggs are speckled as in sivain- 

 soni, not plain as in fuscescens. Attention was first called to this and 

 other evidences of relationship by Mr. Ridgway in the paper above 

 quoted. He then, however, treated nstulatns as specifically distinct. 

 Nothing appears to contradict the view I have adopted, and published 

 as above, that ustvlatus is a geographical variety, the features of which 

 dei)end upon the moisture of the heavily wooded coast region it inhabits. 



All the forms of this species nest alike in bushes, and lay speckled 

 eggs, usually four, measuring about 0.1)1* by 0.G2 inches. The Olive- 

 backed Thrush is a very abundant bird in the Eastern United States 

 during the migrations in April and October. It has not been observed 

 to breed south of Maine and New Hampshire, nor is the evidence satis- 

 factory that it winters north of Florida. As will be seen by the above 

 quotations, it penetrates very far southward in winter. 



TURDUS FUSCESCEXS, Steph. 

 Wilson's Thrush ; Tawny Thrush ; Veery. 



Tardus miistdintis, WiLS., Am. Orn., v, 1812, 98, pi. 43 (itcc Gm., ncc aitrtt.) 

 I'urdus fituccscens, Stepu., Shaw's Gen. Zool. x, 1817, 182.— Cau., J. f. O. 1855, 470 

 (Cuba).— Bd., B. N. A. 1858, 214.— Scl., P. Z. S. 1859, 32(3 ; Cat. 18C2, 2.— Coues &, 



