Cedar Infestation Impacts Avian Communities along the Niobrara River Valley, Nebraska

Authors

  • January S. Frost,

    1. School of Natural Resources, University of Nebraska-Lincoln, 419 Hardin Hall, 3310 Holdrege Avenue, Lincoln, NE 68583-0974, U.S.A.
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  • Larkin A. Powell

    Corresponding author
    1. School of Natural Resources, University of Nebraska-Lincoln, 419 Hardin Hall, 3310 Holdrege Avenue, Lincoln, NE 68583-0974, U.S.A.
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L. A. Powell, email lpowell3@unl.edu

Abstract

Habitat modification has the potential to cause changes in structure and composition of bird communities. Our goal was to determine the response of Songbird community composition to eastern red cedar (Juniperus virginiana) removal in The Nature Conservancy's Niobrara Valley Preserve, Nebraska. We used point counts to survey birds in the riparian matrix of grassland and forest habitats. More than 60 species were recorded on surveys during 2004–2005. We also use the program PRESENCE to determine the response of five species to various habitat components, including cedar density: House Wren (Troglodytes aedon), Spotted Towhee (Pipilo maculates), Ovenbird (Seiurus aurocapillus), Red-eyed Vireo (Vireo olivaceus), and Indigo Bunting (Passerina cyanea). Species richness estimates were highest in open and mixed habitat patches. Local populations of Ovenbirds and Red-eyed Vireos responded positively to cedar density, whereas House Wren numbers declined as cedar density increased. Cedar abundance explained the most variation in bird community similarity between survey points; species richness increased as cedar density decreased. Habitat structure and composition drove variation in community composition and population abundance at fine, local scales within the Preserve. Fine-scale management to remove cedar from local areas should increase diversity of avian species by maintaining a matrix of habitat types. Cedar removal at any scale will affect the composition of bird communities, and we encourage a structured approach to management decisions.

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