Habitat quality of a bird's breeding grounds has been typically evaluated by investigating patterns in nesting success, whereas events that follow fledging have been largely ignored. One especially overlooked aspect of breeding-habitat quality is how habitat affects the survival of young birds after they leave the nest, a period when mortality is notoriously high. We studied survival of fledglings of two mature-forest species, the Ovenbird (Seiurus aurocapilla) and Worm-eating Warbler (Helmitheros vermivorum), to identify intrinsic (e.g., age, condition) and extrinsic (e.g., habitat structure) factors that influence survival. From 2004 to 2007, we radio-tagged 51 Ovenbird and 60 Worm-eating Warbler fledglings in southeast Ohio. We recorded the birds' locations daily and compared vegetation structure at the fledglings' and paired random locations. Using known-fate models in program MARK, we calculated post-fledging survival to be 65% for the Ovenbirds (51 days after fledging) and 67% for the Worm-eating Warblers (31 days after fledging). Fledglings' condition at the time of radio tagging was positively related to survival after fledging, implying carryover effects from the nestling period. Fledglings of both species used dense vegetation with 40–60% more woody stems in the understory than at random locations. Moreover, use of dense vegetation actually promoted survival. Although riparian thickets and tree-fall gaps within some forests may provide abundant habitat for fledglings, other forests may lack the structural attributes that promote fledglings' survival. Our findings highlight the importance of both breeding and post-fledging requirements being considered in avian conservation plans.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 113 • No. 2