The shores of Delaware Bay have long been considered the No. 1 prime stopover real estate for the migratory Red Knot, specifically the rufa subspecies (Calidris canutus rufa) that winters from the Gulf of Mexico to the eastern coast of South America and breeds in Arctic Canada.
In late March, however, a team of 10 ornithologists from South Carolina reported that two islands south of Charleston are just as important (if not more so) for the shorebird’s population. The researchers counted birds on Kiawah and Seabrook islands from mid-February through mid-May 2021 and tallied at least 17,247 knots, which amounts to about 41 percent of the total rufa population of 42,000 birds.
The team published their findings in a 22-page paper and posted it to BioRxiv, a preprint website that hosts papers before they are peer reviewed. (The article was simultaneously submitted to the peer-reviewed journal Wader Study.) One of the authors, Nathan Senner, a professor at the University of South Carolina, called the discovery of so many Red Knots a “staggering and unexpected finding.”
Senner told The State newspaper that the team posted the paper early in hopes that it would help decision-makers in South Carolina ensure greater protections for the birds before horseshoe crabs came ashore to lay their eggs this spring. Harvesters collect the crabs for the pharmaceutical industry, which uses their blue blood to help make vaccines safe. Conservationists argue that the practice reduces the food available for knots and other shorebirds.
“These findings corroborate that Kiawah and Seabrook islands should be recognized as critical sites in the knot network and, therefore, a conservation priority,” the paper states. “As a result, the threats facing the sites — such as prey management issues, anthropogenic disturbance, and sea level rise — require immediate attention.”