HOST RELATIONS OF PARASITIC COWBIRDS 57 



bird eggs have been reported from a single nest of this species (Greene, 

 1917, pp. 193-194). 



Western Wood Pewee 



Contopus sordidulus Sclater 



The western wood pewee is known to be parasitized by two races of 

 the brown-headed cowbird, obscurus and artemisiae—hoth, however, 

 on the basis of very few records. The race obscurus is involved in a 

 parasitized set of eggs taken at Prescott, Arizona, May 31, 1891, as 

 recorded by Bendire (1895, p. 293), and in another set, collected by 

 Stephen Barlow "in Cahfornia" (probably near San Diego). The 

 race artemisiae is involved in four records of parasitized nests found in 

 Alberta by T. E. Randall, and one nest found at Trout Creek Point, 

 British Columbia, by E. M. Tait. In all of these cases the subspecies 

 of the pewee is C.s. veliei Coues. 



Olive-sided Flycatcher 



Nuttallornis borealis (Swainson) 



The olive-sided flycatcher is a rarely reported victim of the brown- 

 headed cowbird (race M.a. artemisiae). I know of three records — 

 two from Alberta and one from California. Each of the Alberta 

 records involves a nest with 3 eggs of the flycatcher and 1 of the 

 parasite, one nest found near Belvedere, June 27, 1925, by A. D. 

 Henderson; the other, at Boyle, June 7, 1934, by T. E. Randall. 

 The third record involves a nest with 2 eggs of the host and 1 of the 

 parasite, taken at June Lake, Mono County, Cahfornia, June 19, 

 1952, by J. B. Dixon, and now in the R. Ki'euger collection in Helsinki, 

 Finland. I am indebted to Mr. Kreuger for the data on this set. 



Vermillion Flycatcher 



Pyrocephalus ruhinus (Boddaert) 



This flycatcher is an uncommonly reported host of the small, 

 southwestern race of the cowbird, M. a. obscurus, but there is reason 

 to believe that it is parasitized more frequently than the records 

 indicate. Two races of the vermillion flycatcher are involved — P.r. 

 Jlammeus in Arizona and California and P. r. mexicanus in the lower 

 Rio Grande vaUey of Texas. Near Brownsville, Texas, J. C. Merrill 

 (1878, p. 142) found a parasitized nest on May 10, 1877; Bendu-e 

 (1895, p. 324) found two such cases in southern Arizona; other 

 Arizona records have come since from Nogales (Dille, 1940, p. 87), 

 from Phoenix (A. M. Ingersold), and from Tucson (N. K. Carpenter). 

 In the collections of the Santa Barbara Museum of Natural History 

 there is a set of 3 eggs of the vermiUion flycatcher with 1 of the dwarf 

 cowbird which was coUected south of Tucson, Arizona, June 2, 1917. 



