Seasonal diets of insectivorous birds using canopy gaps in a bottomland forest

  • Author(s): Moorman, Christopher E.; Bowen, Liessa T.; Kilgo, John C.; Sorenson, Clyde E.; Hanula, James L.; Horn, Scott; Ulyshen, Mike D.
  • Date: 2007
  • Source: Journal of Field Ornithology, Vol. 78, Issue 1, p. 11-20, 2007
  • Station ID: --

Abstract

Little is known about how insectivorous bird diets are influenced by arthropod availability and about how these relationships vary seasonally. We captured birds in forest-canopy gaps and adjacent mature forest during 2001 and 2002 at the Savannah River Site in Barnwell County, South Carolina, and flushed their crops to gather information about arthropods eaten during four periods: spring migration, breeding, postbreeding, and fall migration. Arthropod availability for foliage- and ground-gleaning birds was examined by leaf clipping and pitfall trapping. Coleopterans and Hemipterans were used by foliage- and round-gleaners more than expected during all periods, whereas arthropods in the orders Araneae and Hymenoptera were used as, or less than, expected based on availability during all periods. Ground-gleaning birds used Homopterans and Lepidopterans in proportions higher than availability furing all periods. Arthropod use by birds was consistent from spring through all migration, with no apparent seasonal shift in diet. Based on concurrent studies, heavily used orders of arthropods were equally abundant or slightly less abundant in canopy gaps than in the surrounding mature forest, but bird species were most frequently detected in gaps. Such results suggest that preferential feeding on arthropods by foliage-gleaning birds in habitats reduced arthropod densities or, alternatively, that bird use of gap and forest habitat was not determined food resources. The abundance of arthropods across the stand may have allowed birds to remain in the densely vegetated gaps where thick cover provides protection from predators.

  • Citation: . . Seasonal diets of insectivorous birds using canopy gaps in a bottomland forest. Journal of Field Ornithology, Vol. 78, Issue 1, p. 11-20, 2007.

Pristine Version Available

An uncaptured, or “pristine” version of this publication is available. It has not been subjected to OCR and therefore does not have any errors in the text. However, it is a larger file size and some people may experience long download times.

Download “Pristine” Publication
(PDF; 1.2 MB)


Requesting Publications

You can order print copies of our publications through our publication ordering system. Make a note of the publication you wish to request, and visit our Publication Order Site.

Publication Notes

  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
  • Our on-line publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact the SRS webmaster if you notice any errors which make this publication unuseable.
  • To view this article, download the latest version of Adobe Acrobat Reader.