56 U.S. NATIONAL MUSEUM BULLETIN 233 



southwestern subspecies of the parasite, M. a. obscums, together with 

 the nominate race of the host. These records are: a set of 2 eggs of 

 the flycatcher and 1 of the dwarf race of the cowbird, collected on 

 May 12, 1941, in Santa Clara County, California, by G. Brown, Jr., 

 and now in the R. Kreuger collection, Helsinld, Finland; a fledgling 

 cowbird seen by Legg to be attended by and fed by a western fly- 

 catcher at Point Lobos, California, July 15, reported by Pray (1952, 

 p. 298) and later by Legg (1954, p. 314); a nest containing 1 egg each 

 of the host and of the parasite, found at Eel River Bar, Humboldt 

 County, California, in June 1941, by R. R. Talmadge (1948, p. 273); 

 a fledged dwarf cowbird attended by a western flycatcher at Berkeley, 

 noted by Benson and Russell (1934, p. 219) ; a nest with 2 eggs of the 

 host and 1 of the parasite, found near Gilroy, April 28, 1932, by 

 Eschenberg (Friedmann, 1943, p. 353); and two other parasitized 

 nests reported in another paper (Friedmann, 1943, p. 353), one found 

 near Gilroy, April 28, 1932, by Eschenberg and one at Betebel by 

 Unglish. 



A possible seventh instance, reported by E. A. Stoner (1938), 

 concerns the nest of a black phoebe, taken over apparently by a pair 

 of western flycatchers a nest which, when found, contained 3 eggs 

 of each of the two birds plus 1 of the cowbird. This instance is discussed 

 under the black phoebe. Unknown as a cowbird host until 1934, the 

 western flycatcher appears to be in process of becoming a fairly 

 regular victim in California, where the parasite is extending its range. 



Eastern Wood Pewee 



Contopus virens (Linnaeus) 



The wood pewee is a fairly regular but not a favorite host of the 

 brown-headed cowbird. In my 1929 summary (p. 209) I knew of 

 about three dozen instances; in over 30 years since then, I have noted 

 only two dozen more. While these probably represent only a portion 

 of all the cases which have been found, the fact remains that, in 

 some areas where both the wood pewee and the cowbird are common 

 breeding birds, no such records have been reported. Stewart and 

 Robbins (1958) do not include the wood pewee as a molothrine host in 

 Maryland and the District of Columbia; similarly, there are no 

 records for this flycatcher in the extensive host lists of the annual sur- 

 veys of the Detroit region which the Detroit Audubon Society made 

 from 1952 through 1954. The records culled from the literature, from 

 museum collections, and from correspondence range from Massa- 

 chusetts, Connecticut, New York, New Jersey, and Virginia westward 

 to Ohio, Indiana, Illinois, Michigan, Iowa, and southern Ontario. AU 

 have to do with the eastern race of the cowbird. As many as 4 cow- 



