USGS Cooperative Research Unit
NC State University, Department of Zoology
219 David Clark Labs
Campus Box 7617
Raleigh, North Carolina 27695
In May of 2000 I graduated from the School of Natural Resources at the University of Vermont with a BS in Wildlife Biology. My research interests lie in the areas of Avian Ecology and Conservation Biology. In pursuit of these interests I have worked on wildlife research projects in Alaska, Washington State, Colorado, Belize, Vermont, Maine, Massachusetts, and most recently, North Carolina.
I began working with American Oystercatchers (a shorebird species of conservation concern) while at the Manomet Center for Conservation Sciences in Massachusetts. Dr. Stephen Brown, Brian Harrington, and I conducted a comprehensive aerial survey of the wintering population of American Oystercatchers in the United States. Oystercatchers are large, striking shorebirds that roost in large flocks in the winter along the southeast coast. For the survey we flew nearly the entire coast of the US from the Delaware Bay to the Mexico Border in small, single engine Cessnas at 300-500 feet. In the summer of 2003 we initiated the first study of American Oystercatcher breeding ecology in the Northeast since the early 1980s in cooperation with Monomoy National Wildlife Refuge. I spent the summer on the refuge monitoring breeding success and effects of mammalian and avian predation. I initiated a color-banding and radio-telemetry effort to document survival and local movement and contribute to a larger, cooperative study of survival, dispersal, and migration patterns. In 2003 I was accepted to the graduate progarm in the Zoology Department at North Carolina where I work with Dr. Ted Simons on a study of American Oystercatcher ecology and population dynamics on the Outer Banks of North Carolina.
Natural communities in coastal regions are under increasing pressure from human use, introduced predators, and habitat change. The American Oystercatcher Haematopus palliatus is a useful focal species to study the effect of rapid anthropogenic change on coastal ecosystems. American Oystercatchers are long-lived shorebirds that breed from Maine to Florida and are closely tied to intertidal ecosystems throughout the year. Recent evidence of population declines in several states is raising concern over the status of their populations.
Our research objectives are: (1) understanding the factors affecting American Oystercatcher nesting success in North Carolina, (2) developing population models that incorporate human and natural influences on population trajectories, and (3) understanding migration and dispersal using mark-recapture methods.
Nest success monitoring began on Cape Lookout in 1995 and quickly expanded to include all of Cape Lookout and Cape Hatteras National Seashores. Nests were located and monitored by NCSU grad students and NPS field staff. Nesting success was highly variable, but overall success (25.5%) was low. Raccoons and other mammalian predators were the primary cause of nest failure, accounting for 54% of identified failures. Overwash and drifting sand accounted for an additional 29% of identified failures. Human disturbance directly caused only 3% of identified failures, but disturbance increased the risk of nest loss to predators. In 2005 we initiated a three year study of oystercatcher chick behavior and survival using radio telemetry. We found that oystercatcher chicks move extensively and use the entire beach and dune system. Daily movements of 500 meters were common. This behavior often placed them at risk from vehicles on the beach, and several chicks were killed by vehicles during the course of the study. Since 1999, 47% of chicks in full beach closures on Cape Hatteras survived to fledging, while 27% survived when vehicles were allowed on nesting territories. Chicks in full beach closures used the beach and intertidal zone more than chicks on beaches with vehicles, and they spent less time hiding in the dunes. Cats and ghost crabs were identified as the primary predators during the nestling stage. Major storm events are also a significant factor affecting reproductive success. Nesting success increased by 400% on some islands after Hurricane Isabel struck the Outer Banks in 2003. The storm improved nesting habitat and reduced mammalian predators on islands in the direct path of the storm. Islands of Cape Hatteras National Seashore did not see the same sustained increase in nesting success, possibly because much of the new habitat was lost to road reconstruction.
We developed a demographic model that used estimates of annual fecundity, mark-recapture data from our research in North Carolina, and parameter estimates from the literature to project the effects of periodic hurricanes on Oystercatcher populations over time. The majority of our model projections indicate a declining population. Only in the most optimistic scenario (hurricane renewal event every 10 years) did the population increase. Our predictions are consistent with the overall decline in oystercatchers pairs observed on Cape Hatteras and Cape Lookout National Seashores in the past decade. Oystercatcher pairs have declined 16% at Cape Lookout and 42% at Cape Hatteras since 1999.
We have banded 309 individually color-marked American Oystercatchers in North Carolina since 1999. Resight studies have estimated annual adult survival of 92% and an age of first breeding estimate of approximately 4 years. Working in cooperation with other researchers and volunteers we have identified wintering sites for these banded birds from South Florida to Virginia. We are currently analyzing our mark-recapture database to understand the migration and dispersal strategies of birds in different age classes.