WINTER HABITAT ASSOCIATIONS OF FOUR GRASSLAND SPARROWS IN FLORIDA DRY PRAIRIE

    Authors

    M. G. Korosy; J. S. Reece;R. F. Noss

    Comments

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    Abbreviated Journal Title

    Wilson J. Ornithol.

    Keywords

    Bachman's Sparrow; burn; fire; Florida Grasshopper Sparrow; Grasshopper; Sparrow; Henslow's Sparrow; nonbreeding season; HENSLOWS SPARROWS; BACHMANS SPARROWS; TALLGRASS PRAIRIE; HOME-RANGE; FIRE; GRASSHOPPER; ABUNDANCE; BURNS; LOUISIANA; PATTERNS; Ornithology

    Abstract

    North American grassland birds show long-term population declines that generally exceed the declines of other bird groups. Efforts to conserve grassland birds require knowledge of ecological and habitat requirements during both the breeding and nonbreeding periods of annual life cycles. Nonbreeding habitat associations may affect survival and the acquisition of resources needed for migration and breeding. We focused on the winter habitat associations of a suite of co-occurring grassland sparrows in the dry prairie of south-central Florida, an understudied region within the wintering range of Grasshopper Sparrows (Ammodramus savannarum pratensis) and Hens low's Sparrows (A. henslowii). During the nonbreeding winter months, these two migratory sparrows commingle with resident Bachman's Sparrows (Peucaea aestivalis) and federally endangered Florida Grasshopper Sparrows (Ammodramus savannarum floridanus). We investigated sparrow habitat associations within two defined plant communities of the dry prairie ecosystem, the dry-mesic and wet-mesic prairie, for four prescribed fire treatments over two consecutive winters. Grasshopper and Henslow's sparrows showed higher relative abundance in wet-mesic prairie and Bachman's Sparrows were more abundant in dry-mesic prairie across all fire treatments. Florida Grasshopper Sparrows were detected only in the first and second years post-burn; samples were too small to yield information on potential preferences between the two prairie communities evaluated. We used an information-theoretic approach to select models that best predicted abundances for each species (except Florida Grasshopper Sparrows) based on time since fire and plant community. Abundances of Grasshopper and Bachman's sparrows were best predicted by plant community association and secondly by time since fire; whereas for Henslow's Sparrows, habitat and time since fire were equally important. This is the first concurrent study of these four sparrow taxa in peninsular Florida and indicates that time since fire influences the habitat preferences exhibited by wintering sparrows, but that this role differs across co-occurring species and dry prairie plant communities.

    Journal Title

    Wilson Journal of Ornithology

    Volume

    125

    Issue/Number

    3

    Publication Date

    1-1-2013

    Document Type

    Article

    Language

    English

    First Page

    502

    Last Page

    512

    WOS Identifier

    WOS:000324718700006

    ISSN

    1559-4491

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