NO. II DATA ON THE PARASITIC COWBIRDS — FRIEDMANN 5 



Swainson's warbler 



Limnothlypis swainsonii (Audubon) 



To Kirn's 1917 record of this warbler as a cowbird host in Copan 

 County, Oklahoma (Friedmann, 1963, p. 92), Vaiden (1962, p. 2) 

 added a second instance, found in Bolivar County, Mississippi, and 

 in 1963 still another in Mississippi. He suggested that the Swainson's 

 warbler may prove to be a regular and not infrequent host of the 

 cowbird in the area around Rosedale, Mississippi. 



Grace's warbler 



Dendroica graciae Baird 



On June 30, 1954, near the Grand Canyon village, south rim of 

 Grand Canyon, Arizona, George A. Hall (in litt. March 11, 1964) 

 observed a pair of Grace's warblers feeding a fledged young brown- 

 headed cowbird (M. a. obscurus). 



Golden-cheeked warbler 



Dendroica chrysoparia Sclater and Salvin 



Warren M. Pulich (1965, p. 548) reported that of 19 nests 

 examined by him in a 70-acre tract in the Edwards plateau country of 

 Texas, 15 were found to contain eggs or young of the cowbird. He 

 also had at that time seven other records in addition to the nine listed 

 in my 1963 account. 



Cardinal 



Richmondena cardinalis (Linnaeus) 



The status of the cardinal as a cowbird fosterer varies greatly in 

 different parts of its range, much more than in most host species. The 

 recent study of Scott (1963) in the vicinity of London, Ontario, pre- 

 sents the most extreme situation yet recorded, with an incidence of 

 parasitism of over 60 percent and a greater number of instances (113) 

 than previously known to me (75) from the total range of the cardi- 

 nal. Out of 187 cardinal nests examined, 113 contained eggs of the 

 cowbird, a truly astonishing figure. This indicates how very tentative 

 all estimates of frequency really are, as the cardinal suddenly becomes 

 the 10th most frequently recorded host (previously estimated as the 

 23rd). In spite of 188 records of cowbird parasitism known to me, 

 I do not think the cardinal is victimized more frequently than such 

 species as Traill's flycatcher, Bell's vireo, yellow-throated vireo, or 



