214 U.S. NATIONAL MUSEUM BULLETIN 233 



been recorded a few times previously as a host in Tucunian province 

 and in southeastern Brazil. 



Striped-headed Sparrow 



Aimophila strigiceps (Gould) 



I am informed by Dr. Johann Ottow that at Salta, Argentina, on 

 December 16, 1960, Gunnar Hoy collected a set of eggs of this 

 sparrow containing 1 egg of the shiny cowbird, thereby adding this 

 species to the roster of laiown hosts of the parasite. The record 

 involves the race A.s. dahhenei of the sparrow and the nominate race 

 of the shiny cowbird. 



Chingolo Sparrow 



Zonotrichia capensis (P. L. S. Miiller) 



The recent study by Sick and Ottow (1958) has added greatly to 

 om' knowledge of the relations between the shiny cowbird and this 

 sparrow, the parasite's commonest host in southeastern Brazil and 

 Argentina. Worldng in the province of Rio de Janeiro, Sick and 

 Ottow found 93 nests of the sparrow, of which 57, or 61 percent, were 

 parasitized. This may be compared with Moojen's data (1938, p. 

 17) at Vicosa, Minas Geraes, where 75 percent of the nests were 

 affected. In the latter province, Chagas (in litt.) has found hundreds 

 of nests, and "almost all" contained 2, 3, or 4 eggs of the shiny 

 cowbird, and, in one instance, as many as 14 eggs of the parasite. 

 Allowing even for loose writing, "almost all" must signify a majority. 

 Sick and Ottow never found more than a single egg from any one 

 cowbird in any nest. In the course of 80 days of observations in 

 a carefully watched "control" area about .2 kilometers square, 41 

 female cowbirds deposited 64 eggs. The identity, and hence, the 

 number, of the laying birds was arrived at by a study of the coloration, 

 size, and shell thiclaiess of the eggs. The predilection of the shiny 

 cowbird for the chingolo as a host is indicated further by the fact 

 that, in the same area and during the same period of observation, onl}^ 

 2 nests of a tanager, Ramphocelus bresilius, were parasitized, and 

 none of 31 nests of 9 other potential host species were affected. 



The success of the cowbird in nests of this sparrow may be judged 

 from that fact that 44 percent of the parasitic eggs hatched and 

 26 percent lived to the fledging stage, while 41 percent of the host 

 eggs hatched and 24 percent survived to the fledging stage. 



The data from Minas Geraes refer to the subspecies Zx. subtorquata 

 while the coastal data have to do with another race of the host, 

 Z.c. matutina. 



Dr. Maria Keopcke has recently informed me that, on 15 or 

 more difi'erent occasions, she has seen fledglings of the shiny cowbird 

 (race Ad.h. occidentalis) being cared for by chingolos (race Z.c. 



