PACIFIC COAST AVIFAUNA 



tin County, several on July l'()-21, 1909, one secnrcd July 21 (Waundcrs. 1911a, 

 p. 38) ; Poison, one heard July 26, 1915 (Saunders, 191(;e, p. 85) ; rare at Bill- 

 ings (Thomas, MS). 



Cameron states tliat this species arrives in I\[ay and leaves in August. A 

 specimen from Miles City, dated May 11, 1902, taken by C. P. Hedges, is in the 

 collection of the University of Montana. 



This species nests in June, a nest being found by Cameron, June 26, 1907. 

 at Knowlton. He also states that the young fly by August 21. Silloway states 

 lliat this s|)eeies nests early in June in Fergus County. 



161. 



Chordeiles virginianus hesperis (xrinnell 



I'.VCIFIC NiGIlTHAWK 



All abiuidaut sninini'r resident in the western hall' of 1lii' statr. ranging east 



^*'>iJ^\!!^ -.' ^«?S^'^, ^ 



vv 



^^%>tt 





-^k. .-«>-^ 



sSV*" ^lp^ t-X^"^ "^^ **' ^ '» • -'S*»* ;:^>^ 





■CV 



Fig. IS. P,\(I1-IC NliniTIIAWK I.XtTlSATING III'.I! 



Photo hy A. D. DiBois. 



NkST O.N \ Bi:i) OF MOS.S, NE.\R BELTOX. 



to the western edge of the prairie region. Replaced by s( inulti eastward. The 

 easternmost places where this form has been reported are Milk River, Sun River 

 and Great Falls in the breeding season, and Johnson Lake, Valley County, in 

 migration (Oberliolser, 1914, p. 50). Reported common or abundant in all parts 

 of the state except the Big Hole Basin, where it is rare, only one bird being seen 

 in a season's work (Forrest, 1914, p. 195). 



This species is one of the latest birds to arrive in spring, the date usually 

 being in the first week of June. It leaves in late August or early September. 



