1921 BIRDS OF MONTANA 151 



Spring migration takes place in late ?tlay. Aboiil .May '2^> in Custer and 

 Dawson counties (Cameron, 1908a, p. 51). Siieeimens from Miles City are dated 

 ilay 25 and 28, 1902 (Hedges, coll. Univ. Jlontanai. There are no dates on 

 record later than July, and, therefore, nothing to indieate when the fall migra- 

 tion takes place. 



Nesting begins in June. .V nest eontaining three eggs and a eowlnrd's was 

 found in Custer County, on the Yellowstone Kiver, Juni' 11, .1S1)4 (Cameron, 

 1908a, 11. 51). A nest with four eggs was found l)etween Forts I'nion and Hen- 

 ton, June 19. 1860 (Cooper, 1869h, p. 295). 



294. Wilsonia pusilla pusilla (Wilson) 



\VlLS(l.\ W.VKHLEIi 



A migrant in the eastern part of the state, in'ohahly mainly, if not entirely. 

 in the prairie i-egion. One male taki-n at l''<irt K'eogh. .May 19. 1SS9 ( Thoiiie, 

 1895, p. 21S). A breeding bird taken at r|i|iei- 'I'wd Medn-iiie Lake. Teton 

 County, .Vugust 5. 1914. is an inti'rgrade helweeii this rni'iii and /iih oliiln. 



^^'/ll^^sw fit^^i^^^- 



Fig. 32. Nks'I- ami ioucs oi Ph.i.iii..\ii:ii \V.Miiii,i-.i:. 

 PiPKsin.xE B.\siN-, Ji-.iri.KSDN CeeN'iY: JrxK 16, 

 1910. Nkst kknk.ath rui': hckhs of .\ wim.dw. 



295. Wilsonia pusilla pileolata (Pallas) 



PiLEoL.vTED Warbler 



A common summer resident of the mountains in the western half of tli.j 



