“An exquisitely timed act of nature”
Let’s face it, in our information- and news-soaked culture, we learn a lot of startling things on a regular basis. It takes a lot to surprise us. But this morning’s broadcast of NPR’s Morning Edition had me muttering “holy shit” as I listened on the way to work.
That came when I heard Elizabeth Shogren’s report on an “intrepid” (her adjective, and a good one) species of bird and its annual migration — get this — “from the southern tip of South America to the Arctic and back every year”! Yes, that’s 9,300 miles of flying.
But its long distance flight is not all that’s amazing about this creature. It is one actor is a complex and remarkable happening — what Shogren aptly describes as “an exquisitely timed act of nature.” Shogren reports:
Tens of thousands of red knots stop to refuel in the Delaware Bay just as the world’s largest concentration of horseshoe crabs arrives on the same beaches to lay eggs…. By the time the birds get to Delaware’s shore they’ve been flying for five days straight — and they’re starving….
The birds come here because this is where the strange, prehistoric-looking horseshoe crab comes to lay its eggs.
“There isn’t anything better for these birds to eat,” says Kalasz. “These little tiny horseshoe crab eggs are just packed full of fat,” he adds, holding a cluster of thousands of tiny greenish balls.
At high tide, thousands of these crabs, each the size of a salad bowl, cluster along the water’s edge. The gentle surf is foamy with the males’ sperm. As many as ten male crabs compete to fertilize each female’s eggs.
The superabundance of this nutritious food is essential for the red knots, which double their body weight in about 10 days of gorging, before heading north.
But herein lies a warning, yet another reminder of the myriad ways we are allowing climate change to upset our planet’s delicate ecological balance. Shogren:
The crabs and the birds have to arrive at the same time if the birds are going to make it to the Arctic to nest, and warming water temperatures could prompt the crabs to lay eggs before the birds arrive.
Meanwhile, rising seas and bigger storms are washing away the beaches, which make one of the biggest weight gains in animal kingdom possible, according to Kalasz.
“In a number of years, we could lose this very special place,” he says. “And if that were to occur, I’d feel a tremendous sense of loss.”
The changing climate is creating other risks for the red knot along its migration path, including in the Arctic where it nests.
A tremendous loss indeed.
The report, both text and audio, are here.
