ll>21 BIRDS OF MONTANA 143 



uioiintains, where the species does not breed, antil the middle oi* May. There 

 are few records to sliow just when fall migration takes place. Dates of spring 

 arrival on breeding grounds are as follows : Helena, April 9, 1911 ; Choteau, 

 April 9, 1912; Button, April 3, 1915 (DuBois, MS) ; :\Iissoula, March 19, 1916 

 (Oberholser, 1918, p. 289). Bates of migration in the foothills are from Gallatin 

 County, May 2 to 15, 1909 (Saunders, 1911a, j). 46). The only fall occurrences 

 on record are from Gallatin County, in the mountains in September (Richmond 

 and Knowlton, 1894, p. 307), from Fort Keogh, three seen in the fall of 1892 

 vThorne, 1895, p. 218), and from .Alissoula, October 12, 1915 (Oberholser, 1918, 

 p. 290). 



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

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

 June 18, 1862 (Cooper, 1869b, p. 295). A nest with eggs was found in Custer 

 County, June 16, 1898, and one with young, June 25, 1894 (Cameron, 1908a. 

 p. 49). 



270. Lanius ludovicianus gambeli Ridgway 



California Shrike 



A shrike identified as belonging to this subspecies was taken near Anacond.i, 

 May 14, 1911 (Saunders, 1912a, p. 30, and 1915a, p. 102). 



271. Vireosylva olivacea (Linnaeus) 



Red-eyed Vireo 



A common summer resident at low elevations probably throughout the 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 di- 

 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 propor^''^" "f 

 otlier species. 



The migrations take place in JMay and June, and in August. Four years' 

 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: Cn.ster 

 County, .Alay 23, 1893, and May 16, 1899 (Cameron, 1908a, p. 49) ; Miles City, 

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

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

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

 conda records are in localities where the species does not breed, the rest where it 

 evidently does. 



The only records of the nesting of this species are at Flathead Lake, wiiere 

 two nests with fre-sh eggs were found June 16, 1900 (Silloway, 1901a, p. 21). 



272. Vireosylva gilva gilva (Vieillot) 



p] astern Warbling Vireo 

 A summer resident of extreme eastern Montana, breeding in cottonw^oocl 

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



