By Theresa Stratford for The Island Connection
At the Seabrook Island Town Council Meeting on May 25, Council Member Jeri Finke reported on a special shorebird counting research project that will be wrapping up in the coming weeks with S.C. Department of Natural Resources and the Senner Lab at the University of South Carolina. There have been two students – Maggie Pelton and Sara Padula – studying these shorebirds at Seabrook Island since February of this year. Wildlife Biologist Janet Thibault with SCDNR explained that the students were specifically focused on the red knot. Amazingly, these birds use some of South Carolina’s coast as a layover in their 9,000-mile journey from the bottom of South America to the Arctic, where they will nest.
As the students wrap up their study, Finke wanted to bring awareness to their work so that residents and visitors can take heed and respect the nature of this project. “If you are near the inlet area and see the students, they may ask you to walk wide to avoid the study area so as not to disturb the flock,” Finke reported. “You can imagine how hard counting these birds can be.
The students were not able to conduct the count in 2020 due to the pandemic. Thibault said that this study will reveal important information about the survival rate of the species of red knots, their migratory patterns and population estimates. The Senner Lad reported, “Red knots exhibit one of the most impressive migrations of any bird, completing an annual 18,000-mile round trip journey from their breeding grounds in the Canadian Arctic to their non-breeding areas in Tierra del Fuego each year.
During spring migration (February to May), red knots depend on stopover sites along the Atlantic coast of the U.S to rest and refuel.” One of those stopovers is Seabrook. In February, Thibault presented to the Seabrook Island Birders about why Seabrook is unique compared to other coastal areas along the South Carolina coast. She said that Seabrook has long flats that are gradually exposed as the tide goes down, along with dry beach and inter-tidal zones to the water line that could be 75 to 100 yards at low tide. The birds will take advantage of the feeding as more sand is exposed. Thibault also said that the location of Seabrook alone is unique for the birds. To the south is Botany Bay, which is not developed, and then there is the fact that both Seabrook and Kiawah are bookended by estuarine islands that SCDNR manages. Captain Sam’s Inlet is another productive ecosystem for shorebirds and has been identified as their preferred habitat. Red knots will actually time their migration with the stopover here in the spring, dependent on the spawning of horseshoe crab eggs – one of their food sources. As the spring progresses, Thibault said that the flocks increase and that one year they counted over 7,000 red knots roosting in one place at Captain Sam’s Inlet. “They come here for the food,” Thibault said. White clams are another food source for red knots. “The little white clams are numerous in the Seabrook area and red knots find them to be a great food resource as well, especially before the crabs spawn.” Using geolocating devices, SCDNR has observed many tags from different South American countries. “It blows me away to think about what they have seen along their journeys,” she said. SCDNR has been studying red knots for about 10 years and has gained more data in recent years on how important South Carolina is to their survival. Thibault concluded, “We want people who visit or who reside on Kiawah and Seabrook to know that coastal birds need these areas to survive. It is vital to their success as a species. It is their home too.”
The objectives of the students who have been studying the red knots on Seabrook since February are:
• Conduct weekly resighting efforts from February to May 2021 to identify individually marked red knots and determine the ratio of marked to unmarked individuals along the coast of Seabrook and Kiawah Island.
• Obtain robust estimates of the proportion of the red knot population that utilizes the study area and total stopover duration using mark-recapture data.