On the sandy beaches of the Delaware Bay, in New Jersey, a visitor arrives each May from the southernmost tip of South America. Name: Calidris canutus rufa. The rufa red knot.
What makes the red knot remarkable is its epic journey: 19,000 miles per year, from Tierra del Fuego to the Arctic Circle and back again, one of the longest migrations in the animal kingdom.
The Delaware Bay serves as the most important stepping stone during the red knot’s long spring migration. Famished knots, having flown without rest for as many as seven days straight, arrive on the bay having lost half their body weight. For two crucial weeks, the birds gorge on the eggs of horseshoe crabs. Red knots that gain enough weight will survive the final leg of their journey to the Arctic. Others perish.
In 2015, the U.S. Fish & Wildlife Service listed the rufa red knot as a federally threatened species—it faces threats throughout the Western Hemisphere, from habitat loss in South America to the impacts of climate change in the Arctic. The calamitous overharvest of horseshoe crabs on the Delaware Bay last decade was another major driver of the red knot’s decline—when the starving birds arrived, there weren’t enough eggs waiting for them.
Most recently, in 2016, state and federal regulators approved a plan to permit a 1,400 percent increase in oyster farming on the Delaware Bay. The oyster farms operate on the same tidal flats used by hungry red knots at low tide.
Birds of May, filmed in May 2016 on the beaches of the Delaware Bay, is filmmaker Jared Flesher’s ode to the natural spectacle of the red knot’s annual visit. It’s also an investigation of potential new threats to red knot survival. Not everyone is sure that expanded oyster farming and red knots can happily coexist. Against the scenic backdrop of the bay, Flesher interviews both oyster farmers and the shorebird biologists who fear that an oyster farming boom here could push the rufa red knot closer to extinction.