Comprehensive Description
provided by Smithsonian Contributions to Zoology
Vireo philadelphicus (Cassin)
To the 2 earlier records (Friedmann, 1963:89) of this very rarely reported victim may be added 4 more: 2 parasitized nests found in Ontario (out of a total of 24 nests) recorded in the Ontario nest records files at the Royal Ontario Museum of Zoology; another, also from Ontario (Humber River, 15 June 1915), now included in the collections of the Western Foundation; and a sight record of a Philadelphia vireo attending a fledged young cowbird near Pyramid Lake, Jasper National Park, Alberta, noted by Rogers (1972:881).
Inasmuch as very few sets of eggs of the Philadelphia vireo are to be found in collections, it may be that these 6 records of parasitism indicate a relatively high incidence of cowbird interference.
WARBLING VIREO
- bibliographic citation
- Friedmann, Herbert, Kiff, Lloyd F., and Rothstein, Stephen I. 1977. "A further contribution of knowledge of the host relations of the parasitic cowbirds." Smithsonian Contributions to Zoology. 1-75. https://doi.org/10.5479/si.00810282.235
