MACGILLIVRAY'S WARBLER 249 



egg. Size; a typical set of four measure .71X.56, .70X.5S, .74X.56, 

 •73X.5S- (Figs. I02, 103.) 



Nesting Dates. — Lancaster, N. H., June 8 (Spaulding) ; between 

 Athens and Hartland, Me., June 16 (Knight) ; Listowel, Ont., June 

 3-June 14 (Kells) ; Kalkuska Co., Mich., June 7, Dunham — Onton- 

 agon Co., nestlings, July 15, Peet (Barrows). 



Biographical References 



(i) T. S. Roberts, A Partial List of the Birds of St. Louis and Lake 

 Counties, Minn., Rep. Geol. and Nat. Hist. Surv. Minn, for 1879, IS8. (2) W. L. 

 Kells, Nesting of the Mourning Warbler, (in Ontario), Orn. and 061., XIV, 

 1889, 4; Ottawa Naturalist, XVIII, 1904, 65. (3) E. G. Taboh, Nrsting of the 

 Mourning Warbler, Orn. and OoL, XV, 1890, 68. (4) J. M. Swain, Contribu- 

 tions to the Life-History of the Mourning Warbler, Journ. Me. Orn. Soc, VII, 

 1905, 14. (s) Wm. Brewster, Birds of the Cambridge Region, 353. 



MACGILLIVRAY'S WARBLER 



OPORORNIS TOLMIEI (Towns.) Plate XIX 



Distinguishing Characters. — For a comparison of this species with the Con- 

 necticut and Mourning Warblers, see those species. Length (skin), 5.00; wing, 

 2.50; tail, 2.10; bill, .45. 



Adult {?, Spring. — Head bluish slate, back olive-green, wings and tail olive- 

 green without white markings ; a white mark above and another below the 

 eye, lores black; throat and upper breast blackish or slaty-black rather evenly 

 and widely tipped with grayish white, rest of underparts yellow, the sides 

 greenish. 



Adult <?, Fall. — Similar to adult d in Spring but crown tipped with brown- 

 ish, throat more widely tipped with grayish. 



Young cf. Fall. — Similar to adult c? in Fall but crown olive-brown without 

 slate, lores grayish or brownish, throat and breast yellowish or brownish gray. 



Adult ?, Spring. — Similar to adult <? in Spring but bluish slate of head 

 and olive of back browner; white eye-marks less conspicuous, cheeks and lores 

 grayish, throat and breast gray slightly tinged with brown. 



Adult S, Fall. — Similar to adult $ in Spring but crown brown, browner than 

 back, throat with brownish tinge more pronounced. Not certainly distinguish- 

 able from young c? in Fall. 



Young $, Fall. — like adult $ in Fall but throat averaging browner. 



Nestling. — Not seen. 



General Distribution. — Western United States. 



Summer Range. — A common and characteristic species of the 



western United States, breeding from New Mexico and Arizona to 



British Columbia ; it occurs east regularly to the foothills of the Rockies 



and occasionally far out on the Plains to North Dakota (Musselshell 



