GO 



mUDS OK ILLINOIS. 



Turdus ustiilatus swainsonii ^Cab.) 



OLIVE-BACKED THRUSH. 



Popular synonyms.— Swuliisiiu'ii Thrush; Bwiimp Itobin (Now KiiKlan'l). 



Tunlun .■iiniinnnhii Cahan. Fiiun. Por. I8i.'.-4fi. 1S7.— Uaibd, B. N. All), ltr.8. 216; Cut. N. 

 Am. 15. IHJ'i, No. IM; Hovlew, IHIH, I'J.-Coukh, Key, IliTJ. T': Chock I.l«t. IHTJ. No. S: 

 B. N. W. I«;i. 4; B. Col. Val. 1K7S. ;H.-B. B. * It.. HUI. N. Am. B. I. 1KT4. U. pi. 1. Ili{. t. 



JIulociclila iistiiliila swaitisoni RiDuw. Proc. U. 8. Nat. Mus. Ill , l-Wi, Hit: Norn. N. Am. 

 B. IWI. No. In. 



TurdiiK nntnlaliis mcainsoni Coueb, 2(1 Koy, 1884,248. 



Has. Eiistorn North America. includlDK thu Iloek)r Hountnin dlKtrlct. woKt to the 

 border of thi> Orent Basin: broedinK in the British Province.') ami far Houlhward in 

 the Rocky Mountains: winterinx in moulhoro Union Statu!',* Central America and 

 various parl.s of South America (Ecuador, Peru, Brazil, etc.). 



8r. Cii. Adult. Above uniform olive-brown, more eraylsh in acme oxampleB; 

 a very di.^tinct orbital riuK of bulT; supralorul Rtripu. malar rcclon, chin. Ihroat. and juk- 

 ulum. liKhl liulT. UHually deepest toward sides of head and neck. Jueulum thickly marked 

 with very broad triangular spots of dusky brown (much darker than the color of the 

 crown), these marklncs more cunente anteriorly, and continued alonir sides of the throat 

 In a series of loneitudinal dashes, usually blended into u more or less continuous sub- 

 malar stripe, narrower and unbroken anteriorly: chin and upper part of throat immacu- 

 hito: sides of breast, side.s. and flanks, oIlvuceous-Kray; rest of lower parts pure while: 

 breast marked with distinct transverse spots of deep brownish cray; tibia' lluht brownish 

 «ray. A.\illar8 and lining of wiuK deep drayish fulvous, ml.xed with ochracoous. Kill 

 ilusky, brts;il half of mandible pale (dull llesli-color in life): interior of mouth rich yellow 

 (in life); iris dark brown; tarsi and toes pale brownish, the latter darker. Loneth, 7.— 7 ia; 

 extent of wines. 11.5(1— 12.25: wine, 3.8()-4 1" (3.9G); tail, 2.8(»-3.10(2.!l5): culmen, .50— .55 

 (.52): tarsus, 1 (15-1.18(1.10): middle toe. .(!5-.?2 (.69).t 



"First iiUiinaoi'- Male. Above" much darker than adult, each feothor, exceptine on 

 rump and tail-coverts, with a tear-shaped spot of rich bulT; beneath like adult, but rather 

 more darkly and thickly spotted on the breast, and with narrow terminal bands of dull 

 black on the feathers of the lower breast and sides. From a specimen in my collection 

 shot at Upton, Me.. Aueust 4, 1874." (Buewsteb, Bull. Nutt. Oru. Club. .Tan., 1878, p. 18.) 



Among a large series of specimeus there is miicii variation in the 

 precise shacie of color of the upper parts, some heing much grayer 

 than others. As a rule, examples from the Eocky Mountains are 

 appreciahly grayer than those from the East, and in the case of 

 two or tlireo the difference is very decided; but after a careful com- 

 parison I find that that the ditfcrt'iico is not sullicieutly constant to 

 warrant varietal distinction, especially since the measurements of 

 the two series coincide very closely. I 



•The only record the author has seen Is that of Mr. W. W. Cooke, in the Ontiihnlo'jist 

 ami Oi'lnoi."!. for Oecember. 18sl. p. .s.i, to the effect that this species has been found win- 

 terinein (ho Mississippi bottom, Illiuois, 



t E.\treme and averace measurements of 14 examples. 



1 A series includine 5 males and 2 females from the Eastern States and Rocky Moun- 

 tains averaee us follows: 



Wine. Tall. C'lmen Tarsus M. toe 



Eastern specimens. 

 Western 



3% 

 .S.M 



2 92 



.52 

 .52 



1.12 

 1.09 



.(i9 

 .139 



Seven specimens measured. 



