KEYES AND WILLIAMS BIRDS OF IOWA. 139 



congregate in that vicinity. The extensive swamps bordering the Mis- 

 sissippi River above and below the city, on the Illinois side, form an 

 especially favorable rendezvous for these birds, three species of which 

 are represented nearly in equal numbers — Quiscalus quiscula ceneus, 

 Scolecophagus carolinus, and Agelaius phaeniceus. During September 

 and October, the corn-fields of Iowa are visited by countless numbers- 

 of these black marauders, which wander about in mixed flocks of sev- 

 eral thousands, passing the day in the fields, and the nights in the wood- 

 land or marshes. And it is during this period that so many thousands 

 are poisoned and killed by the farmers. About the first of October, 

 these birds begin to appear from the more northern districts, pouring 

 into the Burlington swamps in myriads, and by the middle of the 

 month immense numbers have here collected. Just before sunrise vast 

 flocks begin to rise out of the swamps and radiate in all directions to- 

 wards the inland corn fields, where they spend the day, returning again 

 to the swamps before sunset. These flocks are often a quarter of a 

 mile in width, and are more than an hour in passing — a great, black 

 band slowly writhing like some mighty serpent across the heavens, in 

 either direction its extremities lost to view in the dim and distant hor- 

 izon. Not unfrequently three or four such vast flocks are in sight at 

 one time. How far away from their night retreats they wander each 

 day has not been observed; an hour and a half before sunset, twelve 

 miles away from the river, the mighty armies of blackbirds are still seen 

 coming over distant hills and directing their courses toward the marshes. 

 It is evident, however, that many miles are daily traversed in their 

 journeys to and from their feeding grounds. Making liberal deductions 

 for any possibility of over-estimating, the numerical minimum of indi- 

 viduals in a single flock cannot be far from twenty millions."* 



Family FRINGILLID/E. Finches, Sparrows, Etc 

 Genus COCCOTHRAUSTES Brisson. 

 Subgenus HESPERIPHONA Bonaparte. 

 [B 303, R 165, C 189, U 514.] 

 Coccothraustes vespertina (Coop.). Evening Grosbeak. Winter 

 visitant; rare, and rather erratic, though its appearance is more regu- 

 lar in the northern than in other portions of the State. It arrives from 

 the north about the last of November, and remains until May. A 

 flock of these birds spent the winter of 1886-7 m the vicinity of Iowa 

 City, and chiefly around the State University. The movements of a 

 flock of more than one hundred individuals which livened the campus 

 for nearly ten weeks, were watched with deep interest. During its 



* Blackbird Flights at Burlington, Iowa.— Charles R. Keyes. The Auk, Vol. V., p. 207. 



