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U. S. P. R. E. EXP. AND SURVEYS—ZOOLOGY-GENERAL REPORT. 
DENDROICA AESTIYA, Baird. 
Yellow Warbler. 
J\Ictacilla aestivn, Gmelin, Syst. Nat. 1, 1788, 996. 
Sylvia aestiva, Latham, Index Orn. II, 1790, 551.— Vieillot, Ois. Am. Sept. II, 1807, 35 ; pi. xcv.— Bonap. Obs. 
Wils. 1826, No. 144.— Aud. Orn. Biog. I, 1831, 476 ; pi. 95, 35.— Nutt. Man. I, 1832, 370. 
Sylvicola aestiva, Swainson, P. Bor. Am. II, 1831, 211.— Bonap. List, 1838.— Aud. Syn. 1839, 57.— Ib. Birds 
Amer. II, 1841, 50 ; pi. 88. 
Rhimamphus aestivns, Bonap. Consp. 1850, 311.— Cabanis, Mus. Hein. 1851, 19.— Ib. Journ. Orn. Ill, 1855,472, 
(Cuba.) 
? Motacilla albicollis, Gmelin, Syst. Nat. I, 1788, 983. 
? Sylvia albicollis, Latham, Ind. Orn. II, 1790, 535. 
? SylviaJlava, Vieillot, Ois. Am. Sept. II, 1807, 31 ; pi. lxxxi. 
Sylvia cilrinella, Wilson, Am. Orn. II, 1810, 111 ; pi. xv. f. 5. 
?? Rhimamphus citrinus, Raf. Journ. de Phys. LXXXVIII, 1819, 417. (Very doubtful if this or any other existing 
species be referred to.) 
Sylvia childreni, Aud. Orn. Biog. I, 1831, 180; pi. 35. (Immature.)» 
? Sylvia rathbonia, Aud. Orn. Biog. I, 1831, 333 ; pi. 65. 
? Sylvicola rathbonia, Aud. Syn. 1839, 58.— Ib. Birds Amer. II, 1841, 53 ; pi. 89. 
Motacilla petechia, Linn. Syst. Nat. I, 1766, 334.— Gmelin, I, 1788, 983. 
Sylvia petechia, Latiiam, Ind. Orn. II, 1790, 535.— Vieillot, Ois. Am. Sept. II, 1807, 32 ; pi. xci. 
Motacilla ruficapilla, Gmelin, Syst. I, 1788, 971. 
?? Sylvia rvficapilla, Lath. Ind. Orn. II, 1790, 540.— Stephens, Shaw, Gen. Zool. X, ii, 1817, 699. 
Sp. Ch. —Bill lead color. Head all round, and under parts generally bright yellow ; rest of upper parts yellow olivaceous, 
brightest on the rump. Back with obsolete streaks of dusky reddish brown. Fore breast and sides of the body streaked with 
brownish red. Tail feathers bright yellrw; the outer webs and tips, with the whole upper surfaces of the innermost one, 
brown ; extreme outer edges of wing and tail feathers olivaceous like the back ; the middle aud greater coverts and tertials 
edged with yellow, forming two bands on the wings. Female similar, with the crown olivaceous like the back, and the streaks 
wanting on the back, and much restricted on the under parts. Tail with more brown. Length of male, 5.25 ; wing, 2.66 ; 
tail, 2.25. (940 ) 
Hub. —United States from Atlantic to Pacific ; south to Guatemala and West Indies. 
The first, second, and third quills are successively a little shorter, though nearly equal, and 
longer than the fourth. The shafts of the wing and tail feathers are white beneath, and 
brown above. The quills, except as mentioned, are of a darker brown than that of the tail. 
The inner edges of the quills are yellow. The yellow on the tail is sulphur color, and lighter 
than that on the rest of the body, which exhibits an almost imperceptible trace of red. There 
are no markings on the head in the male. In the female, however, the extension of the 
olivaceous yellow over the crown gives rise to a yellow superciliary line. A young bird of the 
year is similar to the female, although duller, and lighter beneath. 
A female bird (758) killed in autumn is darker olivaceous above, the color extending over 
the sides of the head, neck, and body. The yellow margins of the wing feathers are much 
more restricted. There is more brown on the tail, this color invading the inner webs to a 
considerable extent. 
Specimens from the Pacific coast appear rather smaller, with less conspicuous streaks than 
eastern, but no other differences are appreciable. 
The Sylvia rathbonia of Audubon is known only by his description of a pair killed in 
Mississippi. Its essential character seems to be in the nearly even tail, with the feathers 
brown and edged externally with yellow, instead of yellow edged with brown. 
In a number of specimens before me I find considerable variation in the extent of brown on 
outer tail feathers. In all very young birds this crosses the shaft to the inner webs, which in 
