News from the Nest: Spectacular Rufa red knots

Rufa red knots / Benjamin Clock

Species spotlight: Rufa red knot

Red knots (Calidris canutus rufa) are medium sized-shorebirds with short legs and a stocky build. They’re rather anonymous in their winter plumage with a pale grey above a white below. However, during breeding season, it’s clear how they got their namesake. Over the summer, they sport a beautiful terracotta orange breast and face below an intricate back of gold, brown, and grey.

Red knots make one of the longest migrations known in the animal kingdom,traveling up to 19,000 miles annually between their wintering grounds in South America and their nesting sites in the Canadian Arctic. To make this arduous journey, they need a lot of fuel. The Southeast – and particularly South Carolina – serves as crucial stopover habitat for red knots to forage on the nutrient-dense eggs of horseshoe crabs. They stay on our shores for almost a month, with the goal of nearly doubling their weight to build up the necessary food storage they need to complete the final leg of their journey to the Arctic.

Unfortunately, like a lot of our coastal birds, red knot populations are under immense pressure – resulting in a population decline of over 85% in recent decades. In South Carolina, horseshoe crabs are harvested by hand when they come to shore to spawn on sandy beaches, primarily during new and full moon high tides in the spring. They are sold to the multi-billion-dollar pharmaceutical company Charles River Labs for use in the biomedical industry and drained of a substantial amount of their blood. This practice has a huge impact on the ecosystem, severely limiting the eggs available for red knots.

This makes our efforts to safeguard their necessary food source and the habitat they rely on even more vital. Last year, the Conservation League and our partners reached a major legal victory that secured necessary protections for the rufa red knot, including safeguarding over 30 beaches and Cape Romain National Wildlife Refuge from horseshoe crab harvesting for a minimum of five years.

Rufa red knots / Benjamin Clock

This spring was the second year of enhanced protections for red knot critical habitat. Here’s the good news: they’re working. 

Last year, biologists with the South Carolina Department of Natural Resources (SCDNR) observed an increase in sightings of shorebirds feasting on horseshoe crab eggs, compared to only seeing one event of less than 100 shorebirds in 2019. In late May of this year, SCDNR biologists observed roughly 2,000 shorebirds, including red knots, feasting on horseshoe crabs on Marsh Island in the heart of the Cape Romain National Wildlife Refuge. Wildlife populations are notoriously slow to recover, and it will take time to see the full scope of our impact, but the on-the-ground observations from birders and biologists are promising.

To learn more about this milestone victory and how you can help contribute to the conservation of red knots, please join us tomorrow, Tuesday, June 25th for a special screening of the film Scarlet Sky and Blue Blood – Conservation of theRed Knot and Horseshoe Crab in the Southeastern U.S.

This new powerful documentary by filmmaker Benjamin Clock takes a close look at the relationship between these two species, the on-the-ground biologists studying them, and the people fighting to protect them. Get your tickets here!

Deveaux Bank / Andy Johnson, Cornell Lab of Ornithology 

Habitat Highlight: Deveaux Bank

With the start of summer, our thoughts return to boating, beach-going, and other outdoor recreation. Our nearness to wildlife-rich waters and beautiful beaches is a major contributor to our quality of life and one of the things that make the Lowcountry so unique. However, we know that some of the same spaces we seek out for recreation are the same places wildlife need to survive, and it’s a delicate dance to balance the bliss on our beaches.

Here’s the good news – we know that setting aside areas for nesting and resting birds works. In the last issue, we squawked about our joy that SCDNR officially closed off Deveaux Bank during nesting season, bringing this vital habitat in line with the protections afforded to our other seabird sanctuaries, like Bird Key-Stono and Crab Bank.

Nearly two months later, we are chirping with excitement at the results. Over Memorial Day weekend, one of the busiest boating days of the year, boaters and water users were observed by SCDNR biologists respecting the closure. Many water users were seen recreating at nearby Botany Island. The few that attempted to land were thankful to learn about theupdated temporary closure and move to other places, leaving Deveaux Bank as a safe space for our coastal birds.

Not only are boaters and water-users happy, but the birds are too! According to SCDNR biologists, thousands of brown pelicans (South Carolina’s new official state seabird!) are nestled in the dense vegetation with downy chicks along the eastern half of the horseshoe-shaped sand spit, closest to Seabrook Island. Along the front beach facing the Atlantic, clusters of royal and sandwich tern colonies were seen on eggs. Black skimmers incubating and gull-billed terns with newly hatched eggs were also spotted.

American oystercatchers (including a 3-week old chick) and black skimmers on Deveaux Bank, June 20, 2024 / SCDNR

On the western side closest to Botany Island, biologists saw signs of a recent wash-over event with wrack scattered throughout but reported a few dry and high spots remain. This past week, roughly 350 black skimmers were scraping in the sand as they scouted out spaces to nest. Multiple American oystercatcher pairs were spotted, including a 3-week-old chick. Roughly two dozen least terns were also seen utilizing what’s left of Deveaux Bank, including a few incubating eggs.

At the intertidal tip of the Botany Island side (the area in years past that remained open to human access), red knots, ruddy turnstones, marbled godwits, sanderlings, and short-billed dowitchers were seen feeding along the water’s edge on horseshoe crab eggs. Although this area lacks the necessary high ground to support successful nesting, these observations reinforce how valuable spaces like this are for the survival of our coastal birds, and how effective and important these seasonal closures are.

We won’t know the official nesting count until later this fall when results fromSCDNR aerial surveys can be analyzed. We also know a lot can happen that impacts the success of a nesting season, from extra high-tides and hurricanes to predation. However, these initial observations paint an encouraging picture of the diversity and quantity of coastal birds that can be seen when safe spaces are conserved and protected. We want to thank Senator Campsen (R-Charleston) and Mayor Bradham of Rockville for their commitment to safeguarding Deveaux Bank and spearheading a thoughtful solution that balances the needs of people and wildlife.

Credit Andy Johnson, Cornell Lab of Ornithology

Photo gullery

Show us your shots! When done properly, photographers can be important advocates for coastal birds. We want to see your best shots, whether it’s a warbler you spotted walking through the Francis Marion National Forest or a peculiar pelican that piqued your interest. Occasionally, we’ll feature shots submitted to be featured in upcoming News from the Nest issues, and we want to see yours!

Please include your name, email address, and where the photo was taken along with your submission.