CCB team spends fifth spring with red knots along South Atlantic Coast
September 25, 2019
By Bryan Watts, Center for Conservation Biology
For the fifth spring season, Fletcher Smith led a field team working with red knots along the South Atlantic Coast. The rufa subspecies of the red knot that migrates within the Western Atlantic Flyway has declined precipitously over the past three decades, leading to its listing as federally threatened. The population is also listed as endangered in Canada and has been declared endangered by the Convention on the Conservation of Migratory Species of Animals. Declines have led to a concerted effort throughout the hemisphere to identify locations with high conservation significance for the population. Much of the work on spring migration has focused on the mid-Atlantic staging areas of Delaware Bay and the Delmarva Peninsula. Much less is known about the staging area along the south Atlantic Coast.
CCB led the first effort to use systematic flag resighting to better understand the role of the South Atlantic in the spring of 2013. Since that time, tens of thousands of knot legs have been scanned and the data show 1) that a significant portion of the rufa population uses the South Atlantic Coast during spring, 2) that birds stage for an extended time period, and 3) that many birds are leaving from this area to fly directly to Arctic breeding grounds. Birds appear to be using the 350 km coast from South Carolina through north Florida as a single staging area and move freely throughout. Distribution within the area varies year to year depending on the distribution of preferred prey.
Work during the spring of 2019 focused on short-distance knots that stage along the South Atlantic. Most of the research and conservation concern over the past 20 years has focused on long-distance knots that migrate from Arctic breeding grounds to winter grounds in extreme southern South America. Much less is known about knots that migrate shorter distances to winter within southeastern North America, the Caribbean Basin, and along the northern coast of South America.
Significant numbers of knots overwinter along the south Atlantic Coast during most years. Numbers along the Georgia and South Carolina coast begin to swell in late March and early April as the overwintering birds are joined by short-distance migrants, presumably from the Caribbean Basin and the Gulf-coast of Florida. This wave arrives well before the long-distance migrants return to stage.
The field team worked several locations where knots were concentrated during the spring of 2019, including Turtle Island, SC, Deveaux Banks, SC, Seabrook Island, SC, Kiawah Island, SC, Ogeechee Bar, GA, and Little Tybee, GA. They documented individuals regularly moving 100 km or more between foraging areas, supporting the notion that birds sample foraging conditions throughout the South Atlantic Coast and use it as a single staging area. The team successfully captured knots in South Carolina and deployed 60 nanotags to allow tracking their movements up the Atlantic Coast.
CCB’s long-term work with knots on the South Atlantic Coast has been conducted in partnership with Georgia Power, the National Fish and Wildlife Foundation, the Georgia Department of Natural Resources Nongame Program, the South Carolina Department of Natural Resources, the US Fish and Wildlife Service, the US Geological Survey, Manomet Center for Conservation Sciences, and The Nature Conservancy.