|
COPYRIGHT 2005 Wilson Ornithological Society
On 17 December 2003 at 08:15 MST, we observed a mixed group of icterids, including 40 Great-tailed Grackles (Quiscalus mexicanus), 20 Bronzed Cowbirds (Molothrus aeneus), and 1 Brown-headed Cowbird (M. ater), in several small palo verde (Cercidium spp.) trees along the southern shoreline of the Eustaquio Balbuena reservoir in Guamuchil, Sinaloa (25[degrees] 28' N, 108[degrees] 06' W). Among these birds was a male Bronzed Cowbird giving a head-down display with its neck ruff flared out, matching the "interspecific preening invitation display" described by Selander and La Rue (1961). The bird remained very still in this position for most of our 5-min observation. A female Great-tailed Grackle spent several minutes within 5-15 cm of the cowbird, lateral to and slightly below it, gently picking at the cowbird's head about eight times. The grackle also delivered six slightly stronger pecks toward the Bronzed Cowbird, but did not cause the cowbird to move from its perch. At the end of this interaction, the cowbird shifted upward along the branch to a position about 30 cm from the grackle. We could not...
Read the full article for free courtesy of your local library.
|
Bookmark this article
Print this article
Link to this article
Email this article
Digg It!
Add to del.icio.us
RSS
