Breeding Behavior of Evening Grosbeaks

Publication Type:Journal Article
Year of Publication:1991
Authors:Scott, AC, Bekoff, M
Journal:The Condor
Volume:93
Issue:1
Date Published:1991
ISBN Number:00105422
Keywords:Coccothraustes, Coccothraustes vespertinus, Fringillidae, Hesperiphona, Hesperiphona vespertina
Abstract:From 1983-1987 we studied the breeding behavior of Evening Grosbeaks (Coccothraustes vespertinus) living in the Front Range of the Rocky Mountains of Colorado. These birds were typically monogamous; at only one of 64 nests (1.6%) was polygny documented. Reproductive behaviors performed by adult males and females were first analyzed across all mating seasons and then with respect to five consecutive nest stages (build/egg laying, incubate, brood, brood/fledge, fledge) and the outcome (success or failure) of individual nests. Adult males and females contributed unequally to the ten most frequently observed behaviors; half were performed almost exclusively by one or the other sex. Males typically fed and protected their mates and what we presumed to be their young; whereas females usually built the nest, incubated, brooded, and also fed their young. Feeding, soft calling from the perch, and fecal removal were performed relatively equally by adult males and females. The success or failure of nests was not associated with patterns of parental behavior. Our results indicate that Evening Grosbeaks formed a partnership in which they divided the effort involved in nest preparation and raising the young at the high altitude where this population was observed.
URL:http://www.jstor.org/stable/1368608
Short Title:The Condor
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith