100 PACIFIC COAST AVIFAUNA No. 14 



194. Xanthocephalus xanthocephalus (Bonaparte) 



VEi.i.()\v-nK.\ni':i> Blackbird 



A siimiiirr I'csident, seattci'ed throuj:tli()iit most of the state, brecdinsj locally, 

 l)ut more liable to be abundant in the migrations. Breeds in marshes of the 

 Transition zone, not above 4500 feet elevation. It prefers marshes of tiiles, but 

 sometimes also nests in cat-tails. The bird is reported as a migrant only in 

 Fergus County (Silloway, 19()l-ia, p. 45). Jt is reported to breed locally in Cus- 

 ter and Dawson counties (Cameron, 1907, p. 897) ; to breed at Swan Lake (Sil- 

 loway, 1903b, p. 802) ; in the Jefferson and Deer Lodge valleys (Saunders, 1912a, 

 )). 27) ; at Three Forks (Saunders, 1911a. p. 40) ; and in Teton and Lewis 

 and Clark counties (Saunders, 1914a, p. 136). I have also noted it breeding 

 at Somers, at the north end of Flathead Lake, and found one empty nest, luit no 

 birds, in rushes at Poison Swamp, near the southern end of the lake. In tlic 

 Bitterroot Valley this species was reported as comiiion in the fall of Ifill, but 

 not seen at any other time (Bailey, MS). 



This species migrates in IMay and September. Dates are as follows: Fridley, 

 Park Clounty, May 13, 1909 ; Silver Bow, May 21, 1911 ; Choteau, May 7, 1912. 

 At Dutton it was first observed IMay 18, 1916 (DuBois, MS). The only fall date 

 that I have is from Choteau, September 8, 1911. In Custer and Dawson coun- 

 ties it is reported to leave at the end of September (Cameron, 1907, p. 397). 



So far as I can find, dates for the breeding of this species in Jlontana arc 

 not on record. It appears to nest irregularly and locally, and I am of the opinion 

 that it does not always return to the same spot each year. I found a nest with 

 five eggs in a small rush slough on the Dearborn River, Lewis and Clark County, 

 July 15, 1911. This is the only occupied nest of which I have any date, and it 

 indicates rather late breeding. In Teton County I seai-ehed for nests several 

 times in June and was unsuccessful. 



195. Agelaius phoeniceus fortis Ridgway 



Thick-billed Redwing 



A common summer resident throughout all parts of the state east of the con- 

 tinental divide. West of the divide this species is also common, but the sub- 

 species has not been definitely determined. Probably it is not fortis. Breeds 

 in the Transition zone, in cat-tail marshes or tules, appearing to have a prefer- 

 ence for the former. The nature of the breeding habitat of this species makes 

 its distribution at that season more or less local, but it is much commoner than 

 the Yellow-headed Blackbird, and more certain to be found where marshes that 

 suit it occur. It is reported commonly by observers from all parts of the state. 

 It occurs rarely in winter in the western part. 



The migrations take place in April and probably October, though definite 

 fall dates are lacking. Arrivals are recorded as follows: Fergus County, April 

 9, 1900, and March 22, 1902 (Silloway, 1903a, p. 45) ; Bozeman, April 17, 1909; 

 Helena, April 9, 1911; Choteau, April 15, 1912; Dutton. April 25, 1916 (DuBois. 

 IMS). In ^Montana I do not think that there is such a difference in the dates of 



