100 PACIFIC COAST AVIFAUNA No. 14 



194. Xanthocephalus xanthocephalus ( IJoiuiparte) 



Yellow-headed Blackbird 



A siinnnei' resident, scattered throughout most of the state, breeding locally, 

 but more liable to be abundant in the migrations. Breeds in marshes of the 

 Transition zone, not above 4500 feet elevation. It i)refers marshes of tules, but 

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

 Fergus County (Sillovvay, 1903a, p. 45). It is reported to breed locally in Cus- 

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

 loway, 19031), p. 302) ; in the Jefferson and Deer Lodge valleys (Saunders, 1912a, 

 p. 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, but no 

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

 Bitterroot Valley this species was reported as common in the fall of 1911, but 

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



This species migrates in ^lay and September. Dates are as follows: Fridley. 

 Park County, May 13, 1909; Silver Bow, May 21, 1911; (^loteau, May 7, 1912. 

 At Dutton it was first observed ]\Iay 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 Montana 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 witli 

 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 searched for nests several 

 times in June and was unsuccessful. 



195. Agelaiiis phoeniceus fortis Ridgway 



Thick-billed Redwing 



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

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

 species has not been definitely (ictci'iniucd. Probably it is not forfls. Ui-eeds 

 in the Transition zone, in cat-tail marshes oi' tules, api)earing to havt^ a prefer- 

 ence for the former. The natui'e of the breeding habitat of this specie's makes 

 its distribution at tluit season more or less local, but it is much comiiionci- tlian 

 the Yellow-headed Blackl)ird, and moi-e certain to be found whei-c mai'slies that 

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

 It occurs rarely in wintei" in tlie western ])art. 



The migrations take place in April and i)robably October, tliough definite 

 tall 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 (DiiBois. 

 .MS). In ]\Iontana I do not think that there is such a difference in the dates of 



