Date of Award
Master of Science (MS)
Katie J. Stumpf
Grassland birds are experiencing major population declines due to habitat loss and fire suppression throughout North America. Large-scale grassland restoration efforts are ongoing, but there is little data on breeding bird productivity on restored habitats, nor on the impact of specific vegetation characteristics on reproductive output. Since 2005, agriculture fields at Panola Mountain State Park, GA have been undergoing restoration to warm-season grasslands; however, up until now there has been no monitoring of nest success or productivity. The goals of this project are to 1) quantify reproductive success and 2) determine which vegetation characteristics are associated with reproductive success. From March-August 2019, we monitored all active nests and recorded nest outcome and vegetation characteristics to determine which variables were most strongly associated with success using Akaike’s Information Criterion (AICc). We found 52 nests of 11 species, with an overall success rate of 34.62%. Thirty-seven of the nests were constructed by grassland obligates (5 species), 38.89% of which were successful. Nest type, plant height, plant height above the nest, and distance from habitat edges were most strongly associated with nest success of all nests. Ground nests were more likely to be successful than shrub nests or birds using nest boxes, likely because the location of nest boxes is decreasing their success. Nests built in taller vegetation, with taller vegetation above the nest, and further from edges were also more successful. All of these factors are tightly linked with predation risk because they provide more concealment and are farther from areas where predators concentrate. We recommend managers design restoration efforts that will ensure appropriate grass height and limit edges near nesting areas to ensure high quality, productive habitat for grassland birds.
Allen, Kayla B., "Several Vegetation Characteristics Affect Reproductive Success of Grassland Birds at a Restored, Warm-Season Grassland in central Georgia" (2020). Biology Theses. 6.