HOST RELATIONS OF PARASITIC COWBIRDS 137 



include the five Dorchester cases taken from the late F. C. Kirkwood's 

 manuscript notes. Despite this, it begins to appear that in eastern 

 Maryland the summer tanager must be a regular fosterer; however, 

 even there it is not one of the most frequently chosen hosts. 



In Oldahoma, Nice (1931, p. 173) has reported three records. 

 In Nelson County, Kentucky, Beckham (1883, p. 141) called the 

 bird an occasional victim. In Texas, it appears to be more than 

 occasionally imposed upon; it has been recorded as a cowbird fosterer 

 in several parts of the state. R. W. Quillin informed me many years 

 ago that the summer tanager was a common host of the cowbird in 

 the environs of San Antonio and he added that, in his extensive 

 observations, he rarely found unparasitized nests of this bird. 

 Simmons (1925, p. 172) similarly found it to be imposed upon in 

 the Austin region, and Sutton (1938, p. 198) noted it in the same 

 capacity in Tarrant County; it has been reported to be parasitized 

 also in Brewster County by Van Tyne and Sutton (1937, p. 94). 



Sutton wrote me that on May 15, 1935, he and J. B. Semple saw 

 a pair of summer tanagers (cooperi) feeding a recently fledged cowbird 

 near Hot Springs along the Rio Grande. This is the only actual 

 record of this host rearing a young cowbird, but there is no reason 

 to think the instance unusual. 



Cardinal 



Richmondena cardinalis (Linnaeus) 



The status of the cardinal as a cowbhd fosterer varies more in 

 different parts of its range than is the case with most birds. In my 

 original summary (1929, pp. 228-229) I observed that, while in some 

 places the cardinal appears to be one of the commonest host species, 

 in other areas it is very much the contrary. Recently, Berger (1951a, 

 p. 29) reported that 10 out of 22 nests (45.4 percent) which were 

 found by him in Michigan were parasitized — a notably high percent- 

 age. He noted that 7 of these 10 nests on which he had sufficient 

 data to allow for analj^sis — containing at least 11 cardinal eggs and 

 13 cowbu-d eggs- — produced no fledged cardinals and only two fledged 

 cowbirds. He attributed this fact to the tendency of the cardinal to 

 desert its nest when a cowbird lays in it. In the same general area, 

 Sutton (1959, p. 81) noted that a cardinal deserted its nest and 4 

 eggs when a cowbird added its own to the clutch. Out of 21 cardinal 

 nests observed by him, only 2 were victimized by the cowbird. 



In the area about Nashville, Tennessee, Monk (1936, p. 33) reported 

 that 'local students have examined thousands of Cardinal nests with 

 only one Cowbhd record, indicating how very rarely this species is 

 parasitized." Even allowing for loose writing and substituting 

 "scores" for "thousands," the tendency seems clear. Laskey (1944a, 



