Abundance and Distribution of Potential
Arthropod Prey Species in a Typical
Golden-cheeked Warbler Habitat
Michael Andrew Quinn
2000 Master's Thesis
Texas A&M University, Department of Entomology
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Entomology
Abstract
Arthropods have diverse functions in ecosystems, including
providing food for resident breeding birds. The Golden-cheeked Warbler,
Dendroica chrysoparia Sclater & Salvin is an
endangered insectivorous song bird that nests exclusively in the
juniper/oak woodlands of central Texas. This study was conducted to
determine the availability of arthropods to the Golden-cheeked Warbler
in its breeding habitat. Regular surveys were made of the arthropods on
four tree species in which the warbler commonly forages. Arthropod
abundance by tree species, height class, date, year and site was
estimated. We surveyed the Long Hollow site for two years and the
Shellberg site concurrently the second year. In general, the difference
between our two study sites was significant but not as great as the
differences among tree species within sites. Although the difference
between sites for some taxa was significant, usually those differences
were proportional across the tree species. Most taxa showed large
differences in abundance between years, particularly those taxa that
were associated with the two species of oaks in our study. In general,
arthropods were more abundant at the lowest height class and were
progressively less abundant with increasing height. Oaks supported
large populations of hemipterans, homopterans and lepidopteran larvae
early in the warbler's nesting season. Ashe juniper supported large
populations of homopterans and lepidopteran larvae in the middle of the
warbler's nesting season. Hymenopterans showed less of a tree species
association than other orders and were abundantly available for a
longer period of time than most orders. Beetles were most abundant in
April. Spiders were the dominant arthropods in terms of overall
abundance, with numbers gradually increasing throughout the period that
the warbler is present in Texas. Twenty-two Golden-cheeked Warbler
gizzards were available for examination. The dominant taxa in these
gizzards were lepidopteran larvae, Hymenoptera, Araneae, Coleoptera,
and Homoptera, closely matching the dominant arthropod taxa found in
the warbler breeding habitat.
Preferred citation:
Quinn, M.A. 2000. Abundance and distribution of potential
arthropod prey species in a typical Golden-cheeked Warbler habitat.
Unpublished Thesis. Texas A&M University, College Station. ix + 182
pp.
See also:
Wharton, R.A., E.G. Riley, M.A. Quinn, J.B.
Woolley, J.S. Schaffner & H.R. Burke. 1996. Invertebrate species
available as food for the Golden-Cheeked Warbler in its nesting habitat.
Office of Research and Technology Transfer. Texas Transportation
Institute, College Station; Texas Department of Transportation, Austin.
98 pp.
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