94 U.S. NATIONAL MUSEUM BULLETIN 2 33 



Elsewhere in its range, the golden-winged warbler has been reported 

 as a \dctim on the basis only of single or very few records. In Massa- 

 chusetts, J. A. Allen (1870, p. 576) recorded one instance. I have 

 learned of but one other case from that state since then. Green 

 (1928) reported one nest with 6 eggs of the warbler and 1 of the 

 cowbird; he supplemented his record with the statement that he 

 occasionally found cowbird eggs in nests of this species with smaller 

 numbers of warbler eggs present. In Wisconsin P. R. Hoy (1885, 

 pp. 102-103) reported a lone instance of cowbird parasitism. No 

 further records for this state were published until 1947, when Robbins 

 (1947) reported two parasitized nests discovered by Richter; a sub- 

 sequent report (1949) gave still others. The cowbird involved in 

 all the records is the typical race, M.a. ater. 



Blue -winged Warbler 



Vermivora pinus (Linnaeus) 



The blue-winged warbler is a fairly frequent victim of the eastern 

 race of the brown-headed cowbird, M.a. ater. Thirty-five definite 

 instances have been noted, rangmg from Connecticut, New York, 

 New Jersey, Pennsylvania, Maryland, and Virginia to Ohio, Indiana, 

 Michigan, Minnesota, Iowa, Missouri, and Alabama. In the 

 summer of 1927 at Cold Spring Harbor, Long Island, New York, 

 I found at least three pairs of blue-winged warblers feeding recently 

 fledged cowbh'ds. As many as 4 cowbird eggs together with 2 of 

 the host's, have been found in one nest: Bailey (1913, pp. 198-201) 

 considered the former similar enough to have been laid by one female. 

 Reiff (1893) reported a nest in Pennsylvania also containing 4 cowbird 

 eggs and only 1 of the warbler. 



One of the hybrids between this warbler and the golden-wing, 

 the so-called Brewster's warbler, has been found to be a victim in at 

 least one instance. Eames (1893, pp. 89-90), who removed the 2 

 cowbird eggs from the nest, reported this case from Connecticut. 



Tennessee Warbler 



Vermivora peregrina (Wilson) 



This northern breeding warbler is a very uncommon victim of the 

 cowbird. Two races of the latter, ater and artemisiae, have been 

 known on a few occasions to lay in the warbler's nests. Brodkorb 

 (1926, p. 249) noted a Tennessee warbler feeding a fledghng cowbird 

 at Duck Lake, Muskegon County, Michigan, on July 12, 1923. 

 T. E. Randall wrote to me many years ago that he had collected a 

 parasitized set of eggs in Alberta. Rowan collected another parasit- 

 ized set at DonatviUe, Alberta, on June 17, 1935, a set now in the 

 collections of the University of Alberta. A third case was found 



