Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Diets of Nestling Gull-Billed Terns in Coastal Virginia

R. Michael Erwin, T. Brian Eyler, Jeff S. Hatfield and Sabrina McGary
Colonial Waterbirds
Vol. 21, No. 3 (1998), pp. 323-327
Published by: Waterbird Society
DOI: 10.2307/1521644
Stable URL: http://www.jstor.org/stable/1521644
Page Count: 5
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Diets of Nestling Gull-Billed Terns in Coastal Virginia
Preview not available

Abstract

We studied the diets of nestling Gull-billed Terns (Sterna nilotica) at colonies in coastal Virginia during the breeding seasons of 1995 and 1996 as part of a long-term study of the species. No previous quantitative assessments had been made of diets of this species anywhere along the Atlantic Coast, and only a few observations had been reported from other coastal areas in the southern United States. During 80 h of observations over the two seasons, 757 feeding observations were made, primarily at two colony sites. We examined how prey type (fish, marine invertebrates, terrestrial prey) and size were influenced by year, tide cycle, season (early and late) and age of the young (small chicks <7 d old versus large chicks >7 d). We did not find significant year differences, but all other factors revealed statistically significant results. Older (>7 d) chicks were fed relatively more terrestrial and marine invertebrate prey than were younger chicks. In June (early season), fewer fish and terrestrial prey were fed to chicks than later (July-August). Most prey were less than one bill length in size, with the majority of the smallest prey being marine invertebrates. Tide cycle influenced prey delivered with terrestrial prey becoming relatively more important during high and ebb periods than during low and flood tides when aquatic prey dominated. The major marine invertebrate prey taken was the fiddler crab (Uca spp.). Terrestrial prey consisted mostly of large odonates and orthopterans. Unlike earlier reports from Europe, we found no regurgitated food pellets in any of the colonies in either year. This study confirms that the Gull-billed Tern is an extremely opportunistic feeder and has adapted to a variety of habitats, helping to explain its cosmopolitan distribution.

Page Thumbnails

  • Thumbnail: Page 
323
    323
  • Thumbnail: Page 
324
    324
  • Thumbnail: Page 
325
    325
  • Thumbnail: Page 
326
    326
  • Thumbnail: Page 
327
    327