Influence of grazing and available moisture on breeding densities of grassland birds in the central Platte River Valley, Nebraska.(Report): An article from: The Wilson Journal of Ornithology

This digital document is an article from The Wilson Journal of Ornithology, published by Wilson Ornithological Society on December 1, 2008. The length of the article is 6510 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 investigated the relationship between grassland breeding bird densities and both grazing and available moisture in the central Platte River Valley, Nebraska between 1980 and 1996. We also compared species richness and community similarity of breeding birds in sedge (Carex spp.) meadows and mesic grasslands. Densities of two species had a significant relationship with grazing and six of seven focal species had a significant relationship with available moisture. Bobolink (Dolichonyx oryzivorus) and Brown-headed Cowbird (Molothrus ater) densities were lower in grazed plots compared to ungrazed plots, whereas Red-winged Blackbird (Agelaius phoeniceus) densities were greater in sedge-meadow plots compared to mesic grassland plots. Bobolink, Dickcissel (Spiza americana), and Brown-headed Cowbird were negatively associated with available moisture with breeding densities peaking during the driest conditions. Our results suggest that wet conditions increase species richness for the community through addition of wetland-dependant and wetland-associated birds, but decrease densities of ground-nesting grassland birds in wet-meadow habitats, whereas dry conditions reduce species richness but increase the density of the avian assemblage. We propose that wet-meadow habitats serve as local refugia for grassland-nesting birds during local or regional droughts.

Citation Details
Title: Influence of grazing and available moisture on breeding densities of grassland birds in the central Platte River Valley, Nebraska.(Report)
Author: Daniel H. Kim
Publication:The Wilson Journal of Ornithology (Magazine/Journal)
Date: December 1, 2008
Publisher: Wilson Ornithological Society
Volume: 120 Issue: 4 Page: 820(10)

Article Type: Report

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