BIRDS OF BOULDER COUNTY, COLORADO 205 



according to Sclater has been recorded with certainty only from the northeastern 

 corner of the state. 



Icterus bullocki, Bullock's Oriole (508) 



Summer resident; common on the Plains. Arrives, May 8-13 (3 records); 

 leaves, September 18-30 (2 records). Gale found young birds in the nest, June 

 18 and 2i. Pierce (Kellogg) reported it as an occasional visitant at Estes Park. 



Euphagus cyanocephalus, Brewer's Blackbird (510) 



Summer resident ; common locally on the Plains and in the parks of the Yellow 

 Pine and Mountain zones. According to Gale it visits the range about the 

 middle of June — presumably after nesting. Arrives, May 3-10 (5 records) ; 

 leaves, September 15 — October 22 (3 records). Gale's notes mention its arrival 

 on March 23, 1886; the date, if correct, is exceptional. Eggs have been found 

 from May 20 to June 5 (Gale). 



Quiscalus quiscula aeneus, Bronzed Grackle (5116) 



Summer resident; rare in the Plains zone. First noted, May 8-19 (2 records) ; 

 the only fall record is September 30. Gale found a nest on May 20, 1886, and 

 apparently in 1887. Blanchard reported it in Boulder Canyon in 1903 (Hender- 

 son). The writer noted it near Boulder in summer only once, June 12, 1910. 



Family FRINGILLIDAE, The Finches, Sparrows, etc. 

 Hesperiphona vespertina montana, Western Evening Grosbeak (514a) 



Winter resident; erratic in its occurrence but occasionally common near 

 Boulder in winter. Henderson reported it abundant at Boulder between 1901 and 

 1909, feeding during the winter on the seeds of the box-elder. Since then it has 

 been noted between October 5 and November 27, 1910. The last spring date at 

 Boulder is May 18. Dille reported young birds near Altona and in the mountains 

 in August and September, 1904 (Henderson), and also reported a nest and eggs at 

 Estes Park on July 4, 1903 (about 9,000 feet). Gale noted the species in Decem- 

 ber, 1888, and March, 1889. 



Pinicola enucleator montana, Rocky Mountain Pine Grosbeak (515a) 



Permanent resident; infrequent. The records for the county appear to be 

 confined to the spruce regions of the Mountain zone, excepting one — a specimen 

 "taken by Gale at 9,000 feet, November 15, 1887" (Henderson). The writer 

 found it in the spruce forests in March, July and September. Henderson's records 

 and the specimens in the University collection were from the spruce region. 



Carpodacus cassini, Cassin's Purple Finch (518) 



Permanent resident; rather infrequent in summer in both the upper part of 

 the Yellow Pine and the lower part of the Mountain zone; in winter it is found 

 chiefly along the edge of the Plains and the lower gulches of the Yellow Pine zone. 



