September 28, 2012
Posted by: Ecological Management
In March 2012, Abby Sterling transitioned from the naturalist staff to begin working on a research project for her graduate work at the University of Georgia. She had been a naturalist since 2008, and was excited to continue to work on Little St Simons Island and contribute to research which serves several purposes that have direct application to the island. Through this research, we have been able to continue our intensive monitoring of nesting shorebirds, focusing on American oystercatchers and expanding to monitoring Wilson’s plovers. Additionally, this project will ultimately provide guidance for focusing monitoring and management on nesting areas that are highly productive for these two species.
Previous research that focused on nesting American oystercatchers indicated that most reproductive failure was the result of nest loss. Beginning in 2008, we worked with St Catherine’s Island, and Department of Natural Resources’ Nongame Conservation program to look at the effectiveness of a head-start program in increasing fledgling success. This involved finding and monitoring nests, collecting eggs and incubating them in incubators at the lodge, and then returning the hatched chicks to their nests on the beach. This sort of work tends to be a big investment in time and resources, and had some mixed results. While some adults managed to raise chicks to fledging without our help in incubating their eggs and some of the incubated chicks survived to fledging, both these control nests and the nests where we returned healthy, mobile chicks often failed as well. We began to suspect that nesting success was largely influenced by the habitat where nests were located, and this led to our current research goals
The main approach of this project was to locate and monitor nests of Wilson’s plovers and American oystercatchers throughout the breeding season, band chicks and monitor them until fledging, and then measure a variety of nest site characteristics from several different spatial scales. We hope to use this information to create models that will allow us to predict not only where these birds will choose to nest, but also what areas of the beach are most successful. It is important to consider nesting habitat from several different spatial scales because as a bird chooses a nest site there are likely many factors that have an influence. We are examining nest sites at a large scale and measuring distance to several landscape features, such as the tide line or marsh edge. We are also measuring habitat features like vegetation and presence of predators at an intermediate scale to represent each bird’s territory, and lastly, we are measuring fine scale features directly around the nest as well. We will compare used and non-used sites to see how variables influence nest-site choice and will also examine if fledging success is influenced by the nest site. Two of the main causes of nest failure are tidal inundation or flooding and predation, so we will look to see if any of these habitat variables influence the risk a nest experiences at a given site. All of this information will help us decide which areas of the beach result in the highest amount of nesting and fledging success. The most successful areas will become high priority areas for management and monitoring in the future, and by focusing on these areas, we hope to increase the reproductive success for these two vulnerable shorebird species. Additionally, we are planning to look at how various climate change scenarios and dynamic beach movements will influence nest success, so that we can plan management strategies that will be beneficial into the future.