294 U. S. NATIONAL MUSEUM BULLETIN 211 



Harold S. Peters (1936) recorded one louse, Myrsidea incerta 

 (Kell.), as an external parasite on this blackbird. 



Fall. — Although not early migrants, the rusty blackbirds desert 

 their breeding haunts as soon as the young are able to fly and to feed 

 themselves. According to Kennard (1920) this occurs about the 

 middle of July in northern New England ; they are no longer seen in 

 solitary pairs, but "again become gregarious, and are seen in small 

 flocks, flying high overhead, between the lakes, or feeding along their 

 shores, getting ready for their southern migration." 



The fall migration begins early in September, but is not in full 

 swing until October, when the birds are pouring through the northern 

 States in immense flocks; the flight continues through November 

 in diminishing numbers, and a few birds linger into December. 

 Tufts tells me that the average date, over a 4-year period, when the 

 species was last seen at Wolfville, Nova Scotia, is October 17. He 

 has one record for early winter, December 16, 1921, "when a bright- 

 colored male was seen feeding on the main highway in company 

 with three blue jays. There was snow on the ground at the time." 



When the flight is well underway it is sometimes quite spectacular. 

 Wendell Taber tells me that, at Lynnfield, Mass., on October 10, 

 1937, he saw a migrating flock that extended for at least a mile, or as 

 far as he could see; the birds were flying southward on a broad front 

 extending from east to west; the wave was from 20 to 40 birds deep 

 from vanguard to rearguard, and only one bird deep vertically. 



Brewster (1906) writes: 



In autumn Rusty Blackbirds are most numerous in the Cambridge Region 

 during the month of October, when roving flocks may be found quite as often in 

 upland fields and pastures as in the lowlands. Wherever they find a field of 

 ripening corn — whether of the yellow, or the sweet, variety — they are sure to 

 visit it almost daily, from the time of their first arrival to that when the last 

 stalks are harvested by the farmer. Early in the seasoD they puncture the kernels 

 and suck out the pasty contents, and after the corn has hardened they sometimes 

 swallow it whole. During the greater part of October they may be seen associating 

 with Robins in "cedar pastures" or even with Blue Jays in oak and chestnut 

 woods. Indeed there are few places in our country districts which they do not 

 visit occasionally at this season. At evening the scattered flocks all fly to the 

 swamps, sometimes congregating in considerable numbers to spend the night 

 together. 



During the fall migration, in October, these birds sometimes gather 

 in large numbers in the tall deciduous trees, oaks, walnuts, maples, 

 and elms that form a dense grove of thick foliage along a stream that 

 flows past my back yard, close to the center of the city and within a 

 stone's throw of brick buildings. Scores of them pour in after sunset 

 in loose, scattering flocks, and move about chattering in the trees, or 



