Identifier

etd-04142005-115636

Degree

Master of Science (MS)

Department

Renewable Natural Resources

Document Type

Thesis

Abstract

Chinese tallow (Triadica sebifera) is a non-native invasive tree that is of particular concern in the Southeastern United States. It has become naturalized in a variety of habitats and can be found in monospecific stands. The use of tallow woodlands by overwintering birds is poorly documented. I compared use of tallow woodlands to use of bottomland hardwood forests by birds in the Mermentau River Basin, Louisiana. Species richness and evenness were greater in the bottomland hardwood sites. Three species were more abundant in tallow woodlands, six species were more common in bottomland hardwoods, and six species exhibited no difference between habitats. Information-theory methodology was used to determine the relative importance of woodland type and certain landscape variables to species richness and bird abundance. Model-averaged parameter estimates and relative Akaike weights were calculated. In most cases, woodland type was a better predictor of species richness and abundance than percent forest cover, distance to nearest forest patch, or the number of forest patches within 1 km. Energy assimilation of tallow fruit by captive birds was measured to determine if apparent metabolizable energy differed between bird species and plant species. Assimilation of tallow fruit pulp differed significantly between birds. Yellow-rumped Warblers (Dendroica coronata) exhibited the highest assimilation of tallow, followed by American Robins (Turdus migratorius) and then Northern Cardinals (Cardinalis cardinalis). Yellow-rumped Warblers, which where more common in the tallow woodlands, were able to metabolize tallow fruit more effectively than wax myrtle (Morella cerifera) and poison ivy (Toxicodendron radicans) fruit. Metabolization of wax myrtle and poison ivy fruit did not differ significantly. Cardinals metabolized deciduous holly fruit (Ilex decidua) more efficiently than either hackberry (Celtis laevigata) or tallow. Overall, bottomland hardwoods supported more bird species and exhibited a higher measure of species evenness. Tallow may provide an alternate food source for some species and could potentially influence the local winter distribution of Yellow-rumped Warblers.

Date

2005

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Frank C. Rohwer

Share

COinS