68 U.S. NATIONAL MUSEUM BULLETIN 233 



inches inside the hole, a factor which suggested to the collector that 

 the parasite may have been unable to enter very far into the nest 

 cavity. Nye (in litt.) wrote to me about yet another parasitized set 

 he collected in Texas, containing 5 eggs of the wren and 1 of the 

 cowbird. 



Carolina Wren 



Thryothorns ludovicianus (Latham) 



The Carolina WTen is an uncommon victim in most parts of its 

 range, but apparently less so in Oldahoma than elsewhere. All of the 

 records involve the nominate subspecies of the wren and all but one, 

 the eastern form of the parasite. The known instances are as follows. 

 Dickey (1914, pp. 158-160) records four parasitized nests in south- 

 western Pennsylvania, one, "found April 22, 1905, was built behind 

 some overhanging sod, in a bank bordering a public road. . . . The 

 bird laid but three eggs when a cowbird deposited one of hers. . . . 

 April 24, I found a nest built in a depression of the sod, at the base of 

 an old apple sprout, which grew on a bank at the roadside. The fe- 

 male incubated three eggs of her own and one of the cowbird's. Some 

 years later two more nests of this wi^en, containing eggs of the cowbird, 

 came under my observation." Jacobs (1924, pp. 52-54) describes 

 another case, also from Pennsylvania. The late R. M. Barnes 

 wrote to me that he had a set of eggs from this wren with a brown- 

 headed cowbird's egg, but he gave no locahty. Nice (1931, p. 136) 

 hsts four parasitized nests from Copan and Vinita, Oldahoma, these 

 four comprising one-fourth of all the nests of this species found there. 

 At Radnor Lake, near Nashville, Tennessee, on July 9, 1933, Crook 

 (1934) found a nest containing 3 eggs of the Carolina wren and 1 of 

 the cowbird. Johnston (in litt.) informed me that, of 11 nests found 

 in Kansas, 2 were parasitized by the brown-headed cowbird. In the 

 vicinity of Austin, Texas, Simmons (1925, p. 172) listed the Carolina 

 wren as a local victim of the dwarf race of the cowbird, M.a. obscurus. 

 Pulich (1961, p. 60) reported the same thing, possibly on the basis of 

 Simmons' statement. 



Rock Wren 



Salpinctes obsoletus (Say) 



The rock wren has been recorded as a brown-headed cowbird host 

 in Kansas and in Colorado. The Colorado instance, recorded by 

 Bendire (1895, p. 437) on information received from W. G. Smith, 

 refers to the western race of the parasite, M.a. artemisiae; this record 

 remains the sole case for the subspecies. In Kansas the eastern, 

 nominate race of the cowbird is the breeding form. In that area L. R. 

 Wolfe wrote to me that he collected a set of 4 eggs of the wren and 2 



