Effects of Brown-headed Cowbird parasitism on provisioning rates of Swainson's Warblers.(Report): An article from: The Wilson Journal of Ornithology
Book Details
PublisherWilson Ornithological Society
ISBN / ASINB003EK9IZ6
ISBN-13978B003EK9IZ2
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This digital document is an article from The Wilson Journal of Ornithology, published by Wilson Ornithological Society on March 1, 2010. The length of the article is 4191 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available immediately after purchase. You can view it with any web browser.
From the author: We studied the effects of brood parasitism by Brown-headed Cowbirds (Molothrus ater) and other factors on food provisioning rates of Swainson's Warblers (Limnothlypis swainsonii), a secretive and poorly understood species of conservation concern. We used time-lapse video systems to collect provisioning data at 25 nests, nine of which were parasitized by Brown-headed Cowbirds. We found strong relationships between feeding rate and brood size with increases from 2.0 feeding visits/hr for nests with a single Swainson's Warbler nestling to 3.0/hr for broods of four. We also found an effect of nestling age with 1.9 visits/hr early and 3.2 visits/hr late in the nestling period. The relationships between cowbird parasitism and provisioning were complex. Nests with brood size of one or three that contained a single cowbird nestling had greater provisioning rates (2.5 and 3.3 visits/hr, respectively) than non-parasitized nests (2.0 and 2.6 visits/hr, respectively). Nests with two cowbirds and no Swainson's Warbler young had greater provisioning rates (3.4 visits/hr) than those with two warbler young (2.4 visits/hr), or one warbler and one cowbird (2.6 visits/hr). The increase in provisioning rate with nestling age was more pronounced with two cowbird nestlings present than in nests with zero or one cowbird nestling. These results suggest that parasitized nests, especially those with multiple cowbird nestlings, can impose greater energetic demands on parents. Food limitation may constrain the ability of Swainson's Warblers to adequately care for both their own nestlings and cowbird young.
Citation Details
Title: Effects of Brown-headed Cowbird parasitism on provisioning rates of Swainson's Warblers.(Report)
Author: Sara Pappas
Publication:The Wilson Journal of Ornithology (Magazine/Journal)
Date: March 1, 2010
Publisher: Wilson Ornithological Society
Volume: 122 Issue: 1 Page: 75(7)
Article Type: Report
Distributed by Gale, a part of Cengage Learning
From the author: We studied the effects of brood parasitism by Brown-headed Cowbirds (Molothrus ater) and other factors on food provisioning rates of Swainson's Warblers (Limnothlypis swainsonii), a secretive and poorly understood species of conservation concern. We used time-lapse video systems to collect provisioning data at 25 nests, nine of which were parasitized by Brown-headed Cowbirds. We found strong relationships between feeding rate and brood size with increases from 2.0 feeding visits/hr for nests with a single Swainson's Warbler nestling to 3.0/hr for broods of four. We also found an effect of nestling age with 1.9 visits/hr early and 3.2 visits/hr late in the nestling period. The relationships between cowbird parasitism and provisioning were complex. Nests with brood size of one or three that contained a single cowbird nestling had greater provisioning rates (2.5 and 3.3 visits/hr, respectively) than non-parasitized nests (2.0 and 2.6 visits/hr, respectively). Nests with two cowbirds and no Swainson's Warbler young had greater provisioning rates (3.4 visits/hr) than those with two warbler young (2.4 visits/hr), or one warbler and one cowbird (2.6 visits/hr). The increase in provisioning rate with nestling age was more pronounced with two cowbird nestlings present than in nests with zero or one cowbird nestling. These results suggest that parasitized nests, especially those with multiple cowbird nestlings, can impose greater energetic demands on parents. Food limitation may constrain the ability of Swainson's Warblers to adequately care for both their own nestlings and cowbird young.
Citation Details
Title: Effects of Brown-headed Cowbird parasitism on provisioning rates of Swainson's Warblers.(Report)
Author: Sara Pappas
Publication:The Wilson Journal of Ornithology (Magazine/Journal)
Date: March 1, 2010
Publisher: Wilson Ornithological Society
Volume: 122 Issue: 1 Page: 75(7)
Article Type: Report
Distributed by Gale, a part of Cengage Learning
