136 U.S. NATIONAL MUSEUM BULLETIN 233 



that he had found this tanager to be victimized in Alberta; and 

 recently, Rogers (1956, p. 399) has reported it as a victim at Melita 

 Island, Montana. In all these cases the cowbird involved is the race 

 artemisiae. 



Scarlet Tanager 



Piranga olivacea (Gmelin) 



The scarlet tanager is the most commonly parasitized species of 

 its family, but it is not among the chief hosts of the brown-headed 

 cowbird. About 50 records have been noted, distributed among 

 the following states : Connecticut, Illinois, Indiana, Iowa, Maryland, 

 Massachusetts, Michigan, Minnesota, Missouri, Nebraska, New York, 

 New Jersey, Ohio, Pennsylvania, West Virginia, and Wisconsin; 

 and Ontario, in Canada (3 records). 



J. P. Norris (1892b, pp. 21-22) stated that, of 22 sets of eggs of 

 this tanager in his collection, 7 contained 1 or more cowbird 

 eggs. All seven of the parasitized sets were collected at Nazareth, 

 Pennsylvania, during two successive summers, 1887 and 1888. Since 

 a fair percentage of the nests were parasitized, it would appear that 

 in this locality the scarlet tanager was a frequent host. In Iowa, Keyes 

 and Williams (1888, p. 34) found the scarlet tanager to be parasitized 

 so heavily that they wrote that the nests of this species "almost 

 invariably" contained from 1 to 3 eggs of the parasite. Mulliken 

 (1899, p. 18) noted a nest containing the surprising total of 9 eggs, 

 5 of which were cowbird, and, judging from the variation in color 

 and pattern, these 5 seemed to have been laid by five different indi- 

 viduals. Hess (1910, p. 26) reported a scarlet tanager incubating 

 4 cowbird eggs with 1 of its own. At Ithaca, New York, I saw a 

 recently fledged cowbird being fed by a female scarlet tanager. 

 Statements to the effect that this tanager may occasionally desert 

 its nest if a cowbird lays in it have been made loosely without sup- 

 porting evidence. 



All the records refer to the eastern race of the cowbird, ater. 



Summer Tanager 



Piranga rubra (Linnaeus) 



The summer tanager is an uncommon victim of the brown-headed 

 cowbird. Eighteen records have come to notice, distributed from 

 Maryland, the District of Columbia, and Virginia to Ohio, Illinois, 

 Kentucky, Tennessee, Alabama, Oklahoma, and southern Texas. 

 These records involve two races of the summer tanager, rubra and 

 cooperi, and two of the cowbird, ater and obscurus. 



Because of the small number of known cases of cowbird parasitism, 

 it is somewhat unexpected to find that Stewart and Robbins (1958, 

 p. 329) noted seven instances in Maryland. These seven probably 



