Habitat selection, food availability, and reproductive success of southwestern willow flycatchers on the South Fork Kern River, California [electronic resource] /

by Copeland, Sylvia Lynn

Abstract (Summary)
The southwestern willow flycatcher (Empidonax traillii extimus) is a federally-endangered neotropical migrant that breeds in the southwestern United States. The population of southwestern willow flycatchers on the South Fork Kern River in California was once thought to be one of the largest E. t. extimus populations. It declined from 38 pairs in 1997 to 12 pairs in 2000. My goals were to examine E. t. extimus habitat selection on the South Fork Kern River, to determine how habitat characteristics and food availability affect E. t. extimus demographics, and to make inferences about possible reasons for the decline. My first objective was to determine southwestern willow flycatcher habitat selection on the Kern on two spatial scales: territory and nest site. Southwestern willow flycathers selected habitat characteristics that appeared to be related to food availability, foraging ecology, or nest cover. Territories within the riparian forest were closer to water and the edge of forest and had fewer cottonwoods than unused areas. Nest sites had denser and more uniform canopy cover and a denser understory than randomly selected sites within territories. My second objective was to determine a relationship between measures of fitness (reproductive success and occupancy frequency) and territory categories (occupied 2 years, occupied 1 year, abandoned).
Bibliographical Information:


School:Virginia Polytechnic Institute and State University

School Location:USA - Virginia

Source Type:Master's Thesis

Keywords:conservation habitat selection quality empidonax traillii extimus southwestern willow flycatcher


Date of Publication:

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