HOST RELATIONS OF PARASITIC COWBIRDS 153 



Lark Bunting 



Calamospiza melanocorys (Stejneger) 



The lark bunting apparently is a fairly common local victim of 

 the northwestern race of the brown -headed cowbird, M.a. artemisiae, 

 but if the species is considered in a general, comparative way, it is a 

 rather infrequent victim. J. A. Allen (1874, pp. 58-59) observed the 

 bird in the Dakotas and Montana and found that, "in a series of eight- 

 een nests, five, or nearly one-third, contained eggs of the Cowbird, 

 two even containing two each, and one had three; while out of twenty- 

 nine nests of other ground-nesting prau'ie birds, collected at the same 

 time and over the same area, not one contained an egg of the Cow- 

 bird . . . ." He concluded that the cowbird formed "no inconsider- 

 able check upon the increase of this bird." Coues (1874, p. 164, and 

 1878b, p. 597) \vi"ote that eggs of the cowbird frequently were found 

 in nests of the lark bunting, and Hoffman (1875, p. 172) noted a para- 

 sitized nest in North Dakota. 



All of the foregoing information was included in ni}^ fu-st account 

 (1929, p. 232). It is strange that, in the succeeding years, only one 

 additional record has come to my attention: a parasitized set of eggs 

 taken in McHenry County, North Dakota, on June 9, 1933, and now 

 in the Brandt Collection of the Carnegie Museum. When we consider 

 that the most recent of the earlier cases was prior to 1878, it is all the 

 more surprising that supplementary information has not been forth- 

 coming. This phenomenon cannot be blamed completely on the 

 dropping off of interest in egg collecting, but, at the same time, there is 

 no reason for thinking that the lark bunting has become immune to 

 cowbird parasitism. 



Savannah Sparrow 



Passerculus sandwichensis (Gmelin) 



The savannah sparrow is a very infrequent victim of the brown- 

 headed cowbird. Although the geographic spread of the recorded in- 

 stances of cowbird parasitism is extensive, there are no more than a few 

 records in any area, and in most there are only single or scattered re- 

 ports. Twenty-eight records have been noted, distributed as follows: 

 Alberta, Manitoba, New Brunswick, Ontario, Quebec, and Saskatche- 

 wan in Canada; Colorado, Maine, Michigan, Montana, New York, 

 North Dakota, Ohio, Oregon, and Utah in the United States. The 

 records involve four races of the sparrow: labradorius in New Bruns- 

 wick; ohlitus in Manitoba, Montana, North Dakota, and Wisconsin; 

 nevadensis in Alberta, Saskatchewan, Colorado, Oregon, and Utah; 

 savanna in Ontario, Quebec, Maine, Michigan, New York, and Ohio. 

 Two races of the cowbird, ater and artemisiae, are involved. 



