1>)21 BIRDS OP MONTANA 14.S 



iiionntains, wlu-i'p the six'uics docs not IjrttHl. until the iiiiildlp of May. Thei-i' 

 are few reeords to show just wlicn fall migration takes phiee. Dates of spring- 

 arrival on breeding grounds are as follows: Helena, April 9. 1911; t'hoteau, 

 April 9, 1912; Dutton, April 'A, 1915 (DnBois, :MS ) ; Jlissoula, Mareh 19, 191G 

 (Oheriiolser, 1918, p. 289). Dates of migration in the foothills are from Gallatin 

 County, xMay 2 to 15, 1909 (Saunders, 1911a, p. 4(1). The only fall oecurrenees 

 on record are from Gallatin County, in tlie mountains in Septi'inher (Riehmond 

 and Knowlton, 1894, p. 307). from Fort Keogh, three sei'U in the fall of 1S9L' 

 ilhorne, 1895, p. 218), and from .Alissoula, October 12, 1915 ( Olierhols, i-, 191;-;, 

 p. 2901. 



The few nesting records in the state show that breeding takes place iu Jane. 

 A nest with six eggs was found on the Missouri between Forts Union and Benton 

 June IS, 1862 (Cooper. 1869b, p. 295). A nest with eggs was found in Custer 

 County, June 16, lcS98, and one with young, June 25. 1S94 (Cameron. 190Sa. 

 p. 49). 



270. Lanius ludovicianus gambeli Ridgway 



C.\LiPORNiA Shrike 

 A shrike identified as belonging to this subspecies was taken neai- Anacond.i. 

 .May 14. 1!)!! ( Saundei-s. I!n2a. p. :!0. and 1915a. |>. 102). 



271. Vireosylva olivacea (Linnaeus) 



Red-eyed Vireo 



A conmiou sununcr resident at low ele'V'ations probably throughout tin- state. 

 Occurs in migration throughout the Transition zone, but breeds only at elevations 

 lower than 4500 feet in the southern part of the state, and below 4000 feet in 

 the northern. Breeds chiefly in Cottonwood groves east of the continental cli- 

 vide. West of it, it breeds in a mixed broad-leaf and coniferous forest, com 

 posed of Cottonwood, tamarack and Douglas fir, with a smaller propoi-*"'-"" "I' 

 other species. 



The migrations take i)laee in .May and June, and in August. Foni' ye.-irs" 

 observations in northwestern Montana give May 24 for an average, and May 19. 

 1896, the earliest date of arrival (Cooke, 1909b, p. 81). Other dates are: Custer 

 County, Jlay 23, 1893, and May 16, 1899 (Cameron, 1908a, p. 49) ; :\liles City. 

 May 23, 1902 (Hedges, coll. Univ. Montana) ; Anaconda, June 3, 1911; and Cho- 

 teaii. May 24, 1912. The only fall dates I have are from Bozeman, August 30, 

 1908, and Logan, Gallatin County, Augu.st 25, 1909. The Bozeman and Ana- 

 conda records are in IoeaIiti(>s where the species does not breed, the n^st where it 

 evidently does. 



The onl.y i-ecords of the nesting of this species are at Flathead Lake, where 

 two nests with fresh eggs were found June 16, 1900 (Silloway, 1901a, [>. 21). 



272. Vireosylva gilva gilva (Vieillot) 



K.\STERN Warbling Vireo 

 A summei- resident of extreme eastern ^Montana, breeding in cottonwood 

 groves in the Transition and Upper Sonoran zones. Probably intergrades west- 



