AVIS-IBIS

Birds of Indian Subcontinent

Foraging Habits of Ruby-Crowned and Golden-Crowned Kinglets in an Arizona Montane Forest

Publication Type:Journal Article
Year of Publication:1984
Authors:Franzreb, KE
Journal:The Condor
Volume:86
Issue:2
Date Published:1984
ISBN Number:00105422
Keywords:Calendula, Corthylio, Corthylio calendula, Regulidae, Regulus, Regulus calendula, Regulus satrapa, Satrapa
Abstract:Foraging behaviors of breeding Ruby-crowned (Regulus calendula) and Golden-crowned kinglets (R. satrapa) in an Arizona mixed-coniferous forest were compared to assess foraging similarity and the use of available habitat components. The species were not significantly different in five of the eight foraging variables examined. Foraging behavior was significantly different (Chi-square test, P < 0.02), for three variables: method of prey attack (Ruby-crowned Kinglet hovered more, Golden-crowned gleaned more), tree species selection (Golden-crowned was more restricted to certain tree species), and relative foraging location (Ruby-crowned used the upper thirds of the trees more frequently). Mean foraging height was similar. Both kinglets differed from a random distribution of use when compared to resource availability for all foraging variables tested (distance from branch tip, selection of tree species, tree height use, foraging height, and relative location). Foraging repertoires of these similar congeners were strikingly alike. Niche theory predicts that two such similar species will modify their foraging behavior to partition the habitat and minimize potential competition. In the case of the kinglets, limited environmental subdivision was demonstrated. Under less favorable habitat conditions, competitive influences may be more important in modifying the foraging behavior of these species.
URL:http://www.jstor.org/stable/1367027
Short Title:The Condor
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