Hooded Warbler Nesting Success Adjacent To Group-Selection And Clearcut Edges In A Southeastern Bottomland Forest

During the 1996, 1997, and 1998 breeding seasons, we located and monitored Hooded Warbler (Wilsonia citrina) nests in a bottomland forest and examined the effects of edge proximity, edge type, and nest-site vegetation on nesting success. Successful Hooded Warbler nests were more concealed from below and were located in nest patches with a greater abundance of >0.5-m-tall switchcane (Arundinaria gigantea) stems than unsuccessful nests. Daily nest survival rates, clutch size, and number of fledglings per successful nest did not differ between nests near edges of selection-harvest openings within the bottomland and nests near edges of clearcuts adjacent to the bottomland. Daily survival rate, clutch size, and number of fledglings per successful nest did not differ among nests 0-50 m, 51-100 m, and >100 m from the nearest edge, and probability of nest survival was not related to proximity to either edge type. However, probability of parasitism by Brown-headed Cowbirds (Molothrus ater) was higher near clearcut edges, and parasitism reduced clutch size and numbers of fledglings per successful nest. The combined effects of edge, especially edge created by the relatively small ( less than or equal to 0.5 ha) group-selection openings, on Hooded Warbler nesting success were minimal. However, our study was conducted in a primarily forested landscape, so cowbird abundance or negative edge effects may have been low relative to agricultural landscapes in the South. Exito de Anidacion de Wilsonia citrina en Sitios Adyacentes a Bordes de Claros Formados por Extraccion de Arboles Seleccionados y por Tala Rasa en Bosques Riberenos del SuresteOriginal Abstract: Durante las epocas reproductivas de 1996, 1997 y 1998, ubicamos y monitoreamos nidos de Wilsonia citrina en un bosque de ribereno y evaluamos los efectos de la proximidad al borde, el tipo de borde y la vegetacion del sitio de anidacion sobre el exito reproductivo. Los nidos exitosos estuvieron mas escondidos desde abajo y se ubicaron en parches de bosque con una mayor abundancia de tallos de Arundinaria gigantea de mas de 0.5 m de alto que los nidos no exitosos. Las tasas de supervivencia diaria de los nidos, el tamano de la nidada y el numero de polluelos emplumados por nido exitoso no difirieron entre nidos ubicados cerca de bordes de aperturas de cosecha selectiva dentro del valle ribereno y nidos cerca de bordes de sitios completamente talados adyacentes al valle. La tasa de supervivencia diaria, el tamano de la