1921 BIRDS OF MONTANA 103 



of the I'oothills. It is I'oinnion throiig'liout the Ti'aii.sitioii /.one, and is found in 

 tlie Canadian, where areas suited to it oeeni' in that zone. It is eonnnon in Wiiite- 

 tail Park, Jefferson County, a large grass area within tlie Canadian zone, situ- 

 ated at an elevation of 71()U feet. 



The migrations take plaee in late Mai'eh or early Aiirii. a)ul in ()etoi)er or 

 Xovember. West of the divide it is so eonnnon in winter that niigratiriii dates 

 cannot be determined witii certainty. In Custer County, eighteen years give an 

 average arrival of Mareh 'M). with the earliest, March 2(1 (lilOT), while the avc^-- 

 age of fall dates is October 20 (Cameron, 11107, p. 'A'.)'.)). Other dates are: 

 Bozeman, March 19, 1909, and March 19, 1911; Helena, ilareh liO, 1911: Cho- 

 teau, April 4, 1912; Highwood, Mareh 27, 1914; Dntton, April 11, 1915, .March 

 17, 1916, and April (3, 1917 (DuBois, MS). Fall dates are: Bozeman, Xovember 

 17, 1908 ; Three Forks, October 17, 1909 ; Button, October 11, 1916 ( Dubois, MS i . 



The Western Meadowlark is a regular winter bird in the lower valleys west 

 of the continental divide, such as the Bitterroot Valley and the valley of the 

 Flathead River about Kalispell. East of the divide it occurs in winter in scat- 

 tered localities and in small numbers, it is reported to wintei' in ('usti'r ('ounty 

 (Cameron, 1907, p. 4(10), in Gallatin County (Satuiders. l!)lla, |>. 40 i , at Helena 

 (.Saunders, 19111i, p. lOS), and at Billings (Thomas. MS). 



Nesting begins the latter half of May, and eggs may be found from then 

 until late June. Young are leaving the nests from the middh' of -luue until 

 early in August. Whether there are two broods or not is not apparent, as tlier^' 

 seems to be no general break in the finding of eggs. The earliest nest on record 

 is one from the Bitterroot Valley, May 12, 1911, and the latest I'ecord of nesting 

 is that of .young unable to fl,v, August 10. 19(»S. in tln' same locality (Bailey. 

 i\IS). The latest eggs are June 28. 1S74, on l'orcu))ine Cri'ck (Cones, lS74b, p. 

 <)03 ) , but it is probable that eggs may be found uuich later than this. 



198. Icterus galbula (Linnaeus) 



Baltimore Oriole 

 A rare summer resident of extrenu' eastern Montana. Three specimens 

 were taken by Dr. Hayden on the Yellowstone and at the mouth of the Powder 

 River in 1856, one of which is dated August 4 (Baird. 1858. p. 549). Mr. 

 Thomas wrote me that he saw a bird of this species at Glendive in August. 1!)09. 

 These appear to be the only records. 



199. Icterus bullocki (Swainson) 



Bullock Oriole 



A sunuiier resident of the ])rairies and lower mountain valleys, breeding in 

 Cottonwood groves along streams, mainly in the Cpper Sonoran zone. Common 

 in eastern Jlontana, and becoming I'are westward, but found throughout the 

 state in suitable localities. Rare at elevations above 4000 feet in the northern 

 part of the state, and above 4500 in the southern. Because of this, this species 

 is not recorded from southwestern ^Montana west of Gallatin Coiuity, where the 

 valleys are nearly all aliove 4500 feet. The only place where I have found it 



