Provisioning of nestling Dickcissels in native warm-season grass field buffers

Wilson Journal of Ornithology
By: , and 

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Abstract

We used video cameras in 2008–2009 to record provisioning activities at Dickcissel (Spiza americana) nests in and around Conservation Reserve Program field buffers in north-central Mississippi, USA. We simultaneously observed foraging flight distances of parents. Provisioning rate (P  =  0.412), biomass (P  =  0.161), and foraging distance (P  =  0.159) did not increase with nestling age. Parents delivered larger items to meet demand associated with older nestlings (P  =  0.010–0.001). This suggests energetic costs of changes in prey selection were less than costs of increasing the number or distance of provisioning trips. Presence of male helpers increased provisioning rate (P < 0.001) but not biomass (P  =  0.992) because males brought smaller prey items (P  =  0.001–0.021). Presence of observers 30 m from the nest reduced provisioning rates (P  =  0.005) and biomass delivered (P  =  0.066). Lack of habitat effects for any aspect of provisioning suggests grass field buffers provided nestling food resources similar to surrounding habitats. Use of continuous video monitoring of nest activity allows well-concealed activities including provisioning and male helping to be directly observed and better quantified.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Provisioning of nestling Dickcissels in native warm-season grass field buffers
Series title Wilson Journal of Ornithology
DOI 10.1676/11-152.1
Volume 124
Issue 2
Year Published 2012
Language English
Publisher The Wilson Ornithological Society
Contributing office(s) Coop Res Unit Atlanta
Description 12 p.
First page 298
Last page 309
Country United States
State Mississippi