46 Saunders, Birds of Gallatin Co., Mont. [j^ 



June 18, 1909. I saw it but once in 1908, but it was very common in 1909, 

 when I found two nests in the shade trees of Bozeman in August. I be- 

 lieve that this difference in abundance was due to the relative abundance of 

 service-berries, which form a large portion of the food of the young. 



166. Lanius borealis. Northern Shrike. — Common winter resi- 

 dent in the valleys. This species arrives early in October and leaves by 

 the last of March. I have seen it in mountain parks as high as 7,000 feet 

 in November. An adult male, taken at Three Forks in February, 1910, 

 had the typical measurements and markings of the form described as L. 

 b. invictus. Should this form be accepted as a subspecies it should be 

 included in the list of Gallatin County birds. 



167. Lanius ludovicianus excubitorides. White-rumped Shrike. 



— Summer resident. Richmond and Knowlton recorded it as common in 

 the valleys. I have not seen it in summer but noted it quite commonly 

 from May 2-15, 1909. 



168. Vireosylva olivacea. Red-eyed Vireo. — Summer resident in 

 cottonwood groves in the valleys. Not common. I have noted it near 

 Logan and on a small island in the Gallatin River near Salesville. During 

 migrations in late August I have occasionally seen it in Bozeman. 



169. Vireosylva gilva swainsoni. Western Warbling Vireo. — 

 Common summer resident in cottonwood groves in the valleys and about 

 the edges of mountain parks to 7,500 feet. It arrives in the latter part 

 of May and leaves late in August. It is quite common in the shade trees 

 of Bozeman, where it builds beautiful nests, using cottonwood down largely 

 in the construction. 



170. Vermivora celata lutescens. Lutescent Warbler. — Mi- 

 grant. This bird was quite common in the valleys and foothills from 

 May 8 to June 2, 1909. 



171. Dendroica sestiva. Yellow Warbler. — Common summer 

 resident in willow thickets in the valleys. This species arrives about May 

 20 and leaves late in August. 



172. Dendroica auduboni. Audubon's Warbler. — Common sum- 

 mer resident in the mountains. This species is abundant in the foothills 

 during migrations. It first appears early in May and leaves about the 

 middle of October. 



173. Seiurus noveboracensis notabilis. Grinnell's Water- 

 Thrush. — Summer resident. Not common. A few of these birds may 

 be found throughout the summer in the willow swamps near Bozeman. 

 They arrive about the end of May. 



174. Oporornis tolmiei. Macgillivray's Warbler. — Common 

 summer resident in willow and wild-rose thickets in the valleys and foot- 

 hills. It arrives late in May. 



175. Geothlypis trichas occidentalis. Western Yellow-throat. 



— Common summer resident in similar places to the above species but 

 somewhat more abundant. Arrives about May 20. 



176. Wilsonia pusilla pileolata. Pileolated Warbler. — Common 



