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
Return to Texas
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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