Graduate Program
Biological Sciences
Degree Name
Master of Science (MS)
Semester of Degree Completion
2009
Thesis Director
Eric Bollinger
Thesis Committee Member
Stephen Mullin
Thesis Committee Member
Paul Switzer
Abstract
The Red-headed Woodpecker (Melanerpes erythrocephalus) is a classic oak savanna species that has suffered significant population declines caused, in part, by extensive loss of savanna habitat and agricultural development. Despite consistent data that reveal a dramatic decline throughout much of their range, few studies have examined other possible explanations. In an effort to determine potential causes for their continued decline (as well as add to existing knowledge of nesting biology), we examined nest success and nesting micro-habitat features. We compared micro-habitat variables at: 1) golf and non-golf course sites, 2) successful and failed nest sites, and 3) nest and random sites. Furthermore, we examined nestling feeding rates to address previously unknown aspects of Red-headed Woodpecker life history. We examined provisioning patterns via the following measures (at four different nestling age classes): 1) time in the nest feeding and/or brooding by adults, 2) time between feeding and/or brooding trips, and 3) feeding rates.
Data from 28 Red-headed Woodpecker nests and their surrounding habitat were incorporated into a series of logistic-exposure models. The logistic-exposure models were designed to predict what specific explanatory variables had a significant effect on nest success. We discovered that nest success was higher in non-golf course habitat (59%) than in golf course habitat (51 %; although, not significantly so). We found that cavity height was the most important predictor of nest success. Nest success was expected to drop dramatically as nest cavity height fell below 10 m.
In a comparison of nest sites on golf courses and in other habitats, mean canopy cover at random points was higher in other (i.e. non-golf course) habitats, and mean openness at random points was higher in golf course habitat. Golf course nest cavities had a more easterly orientation, and non-golf course nest cavities had a more southerly orientation. In a comparison of successful and failed nests, mean tree height was greater in successful nests. Furthermore, mean cavity height of successful nests was greater than that of failed nests. Random focal trees were significantly taller than nest site trees, and nest plots had significantly more snags and cavities than random plots. Red-headed Woodpeckers nested significantly more in dead trees (snags) than would be expected based on availability.
We determined that age class had a significant effect on the time spent in the nest feeding and/or brooding nestlings. Parents spent an average of 67 sec in the nest at the youngest age class declining to an average of 7 sec in the nest at the oldest age class. Age class, location, and their interaction had no significant effect on feeding rate or the time between feeding trips.
Conservation of snags and large DBH trees should provide greater access to nesting, roosting, and foraging sites for the Red-headed Woodpecker. Researchers should examine the efficacy of artificial substrate and tree branch girdling in creating more nesting site opportunities. Furthermore, estimates of juvenile and adult survival are of great importance. Future provisioning studies should incorporate nestling quantity, sex-specific foraging patterns, and nestling thermal ecology.
Recommended Citation
Hudson, Nathan Cole, "Nest Success, Nesting Habitat, & Nestling Feeding Rates Of Red-Headed Woodpeckers In East-Central Illinois" (2009). Masters Theses. 67.
https://thekeep.eiu.edu/theses/67
