Breeding Bird Response to Cattle Grazing of a Cottonwood Bottomland

Publication Type:Journal Article
Year of Publication:1987
Authors:Sedgwick, JA, Knopf, FL
Journal:The Journal of Wildlife Management
Date Published:1987
ISBN Number:0022541X
Keywords:Emberizidae, Erithacus, Erithacus rubecula, Geothlypis, Geothlypis trichas, Icteria, Icteria virens, Incertae Sedis, Mimidae, Muscicapidae, Parulidae, Pipilo, Pipilo erythrophthalmus, Toxostoma, Toxostoma rufum, Troglodytes, Troglodytes aedon, Troglodytes troglodytes, Troglodytidae, Turdidae, Turdus, Turdus migratorius
Abstract:We studied avian habitat relationships and the impact of grazing on breeding densities of selected migratory birds in a plains cottonwood (Populus sargentii) bottomland in northeastern Colorado. Five 16-ha plots served as controls and 5 were fenced and fall-grazed October-November 1982-84 following a season of pre-treatment study in the spring of 1982. We focussed our analysis on bird species directly dependent on the grass-herb-shrub layer of vegetation for foraging, nesting, or both. The guild included house wren (Troglodytes aedon), brown thrasher (Toxostoma rufum), American robin (Turdus migratorius), common yellowthroat (Geothlypis trichas), yellow-breasted chat (Icteria virens), and rufous-sided towhee (Pipilo erythropthalmus). Moderate, late-fall grazing had no detectable impact on calculated densities of any of the 6 species, implying that proper seasonal grazing of a cottonwood floodplain is, at least initially (3 years), compatible with migratory bird use of a site for breeding. Habitat associations suggested that common yellowthroats and yellow-breasted chats were most unique and most likely to respond negatively to higher levels of grazing. We suggest that these latter 2 species are appropriate ecological indicators of the quality of ground-shrub vegetation as breeding bird habitats in lowland floodplains of the Great Plains.
Short Title:The Journal of Wildlife Management
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith