Some of the material in is restricted to members of the community. By logging in, you may be able to gain additional access to certain collections or items. If you have questions about access or logging in, please use the form on the Contact Page.
Walters, E. L. (2004). Estimating Species Interactions in a Woodpecker Tree-Hole Community at the Individual,
Population, and Community Levels. Retrieved from http://purl.flvc.org/fsu/fd/FSU_migr_etd-1299
The endangered red-cockaded woodpecker (Picoides borealis) is a keystone species in the southeastern United States where it excavates tree holes in living pines trees. An understanding of the interactions among the species using the tree holes may indicate whether they affect red-cockaded woodpeckers negatively. In the Apalachicola National Forest of northern Florida, I conducted a series of experiments at the individual, population, and community level to determine the nature of these interactions. Short-term interactions at the individual level were quantified by removing red-cockaded woodpeckers and red-bellied woodpeckers (Melanerpes carolinus), the two numerically dominant species in the assemblage and by temporarily occluding tree holes. Reciprocal effects of each species on the other were demonstrated over periods as short as 48 hours. Surprisingly, at the population level, red-cockaded woodpecker group size and female persistence were reduced in areas where red-bellied woodpeckers were removed. The immigration rate of floater red-bellied woodpeckers was inadvertently increased and thereby increased the disruption within red-cockaded woodpecker family groups. At the community level, Markov models were used to measure the interaction among members of the species assemblage. Time and location did not affect the matrix transition probabilities. In a district of the forest where the red-cockaded woodpecker population is declining, the removal of red-bellied woodpeckers allowed the population of flying squirrels (Glaucomys volans) to increase. In a district where the red-cockaded woodpecker is stable, the removal of red-bellied woodpeckers did not have any effect. When matrices were projected at equilibrium, 50% more red-cockaded woodpeckers and 50% less red-bellied woodpeckers were predicted in the stable population than in the declining population. The interaction of both red-bellied woodpeckers and flying squirrels with red-cockaded woodpeckers is probably contributing to the decline of red-cockaded woodpeckers in parts of the Apalachicola National Forest and possibly elsewhere. This study underscores the need for a combination of empirical approaches that allow investigators to identify mechanisms of species interactions at the individual level, the fitness effects at the population level, and the overall effects on the assemblage at the community level.
Red-Bellied, Red-Cockaded, Competition, Tree Hole, Woodpecker, Community Ecology
Date of Defense
February 27, 2004.
Submitted Note
A Dissertation Submitted to the Department of Biological Science in Partial Fulfillment of the Requirements for the Degree of Doctorate of Philosophy.
Bibliography Note
Includes bibliographical references.
Publisher
Florida State University
Identifier
FSU_migr_etd-1299
Use and Reproduction
This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them.
Walters, E. L. (2004). Estimating Species Interactions in a Woodpecker Tree-Hole Community at the Individual,
Population, and Community Levels. Retrieved from http://purl.flvc.org/fsu/fd/FSU_migr_etd-1299