THE COWBIRDS. 



By Maj. Charles Bendire, 

 Honorarii Curator of the Oological Collections, U. S. National Museum. 



Among our American birds comparatively few present such an inter- 

 esting tield for systematic investigation and study of their habits and 

 mode of reproduction as the Cowbirds or Cow Buntings. 



The family to which they belong, the Icteridce, containing such familiar 

 birds as the Bobolink, the Oriole, Blackbirds, etc., is confined to the 

 American continent, and the genus Molothrus (with its subgenus Cal- 

 lothrus) is represented by 12 species and subspecies. Of these, three are 

 found in the United States, namely: Molothrus ater, Molothrus ater 

 obscurus, and Callothrus robustus; and a fourth, CaUothrus (erieus, is a 

 resident of western Mexico and portions of Central America. The 

 remaining species are confined to South America. Callothrus armenti 

 is found on the coast of Colombia and Venezuela ; Molothrus atroniteus 

 in Guiana, Venezuela, and Trinidad; M. purpurascms in western Peru; 

 M. cassini in Venezuela and Colombia; M. frimjillarius in Brazil; M. 

 honariensis in Argentina, Paraguay, Bolivia, and Brazil; 31. rufoaxil- 

 laris in Argentina and Uruguay, and .1/. biidius in Argentina, Para- 

 guay, and Bolivia. 



Respecting the general habits of some of the species, comparatively 

 little is as yet known excepting those found in the United States (but 

 even here a great deal remains to be learned) and the three last, which 

 have been pretty fully described m Sclater and Hudson's excellent 

 work on Argentine ornithology. 



It is probable that nearly all these species are parasitic to a greater 

 or less degree, laying their eggs in the nests of other birds and letting 

 them perform the duties of incubation and rearing the young, with the 

 exception of Molothrus badius, the Baywinged Cowbird, which occa- 

 sionally builds a nest of its own or appropriates nests of other species, 

 but incubates its own eggs or cares for its young like other respectable 

 members of the Avian family. 



This same parasitic instinct is also found among members of the 

 more cosmopolitan family of the Cuckoos, notably with Gueulus cano- 

 rus, the European Cuckoo, about which a great deal of interesting lit- 

 erature has already been published, and the same traits, only in a much 

 more modified degree, are also said to be occasionally observed in at 

 least one of our North American species, the Blackbilled Cuckoo, Coc- 

 cijzus erythrophthalmus^hnt no such instance has as yet come under my 

 own observation, and I consider it of rare occurrence. 



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