| Type of Document |
Dissertation |
| Author |
Blanc, Lori Ann
|
| Author's Email Address |
lblanc@vt.edu |
| URN |
etd-07272007-151106 |
| Title |
Experimental study of an avian cavity-nesting community: nest webs, nesting ecology, and interspecific interactions |
| Degree |
PhD |
| Department |
Biological Sciences |
| Advisory Committee |
| Advisor Name |
Title |
| Walters, Jeffery R. |
Committee Chair |
| Adler, Lynn S. |
Committee Member |
| Haas, Carola A. |
Committee Member |
| Jones, Robert H. |
Committee Member |
| Stauffer, Dean F. |
Committee Member |
|
| Keywords |
- cavity-nester
- ecosystem engineer
- snag
- structural equation modeling
- red-cockaded woodpecker
- Colaptes auratus
- nest web
- Picoides borealis
- longleaf pine
- northern flicker
- endangered species management
- indirect interaction
- keystone species
|
| Date of Defense |
2007-07-17 |
| Availability |
unrestricted |
Abstract
Cavity-nesting communities are structured by the creation of and competition for cavities as nest-sites. Viewing these communities as interconnected webs can help identify species interactions that influence community structure. This study examines cavity-nesting bird community interactions within the fire-maintained longleaf pine (Pinus palustris) ecosystem at Eglin Air Force Base, Florida. In chapter 1, I provide a background review of the ecology of my study system. In chapter 2, I use nest webs to depict the flow of cavity-creation and use at Eglin. I identified 2 webs into which most species could be placed. One web contained 6 species associated with pines. The second web contained 5 species associated with hardwoods. Red-cockaded woodpeckers (Picoides borealis) and northern flickers (Colaptes auratus) created most cavities used by other species within this community. In chapter 3, I describe snag densities and nest-site selection of the cavity-nesting bird community at Eglin. Large, mature pine snags were abundant, exceeding other reported densities for southern pine forests. Pine snags were heavily-used, despite the abundance of available red-cockaded woodpecker cavities in living pine. Hardwood snags accounted for 10% of nests found, and were used by 12 of 14 species. Diameters of nest-trees and available snags were below the range of optimal nest-snag diameters reported in other studies, indicating the need for site-specific snag management guidelines. In chapter 4, I combine a study of basic ecological principles with endangered species management to examine interactions within the cavity-nesting bird community at Eglin. I used a nest web to identify a potential indirect interaction between the red-cockaded woodpecker and large secondary cavity-nesters, mediated by the northern flicker. I used structural equation modeling to test a path model of this interaction. By experimentally manipulating cavity availability, I blocked links described in the model, confirming cavity creation and enlargement as mechanisms that influence this indirect relationship. I demonstrated that a red-cockaded woodpecker cavity-management technique could disrupt this indirect relationship by affecting northern flicker behavior, and provided an empirical example of how, in interactive ecological communities, single-species management can have indirect effects on non-target species.
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| Files |
| Filename |
Size |
Approximate Download Time
(Hours:Minutes:Seconds)
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| 28.8 Modem |
56K Modem |
ISDN (64 Kb) |
ISDN (128 Kb) |
Higher-speed Access |
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LoriBlancETD.pdf |
2.85 Mb |
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