Shorebird migration underway
A thunderstorm popped up at St. Marks NWR on Friday morning, just as I arrived at the refuge at 6:00 am. It was over in fifteen minutes and a bright half-moon peeked through a break in the clouds and reflected off a puddle as I unlocked the gate at the Double Dikes and headed out to start a shorebird survey.
I got started around sunrise. It took me six hours to run a seventeen-mile circuit of St. Mark’s interior ponds and pools, stopping frequently to pull out my scope and count groups of shorebirds. I had to detour to avoid a section of levee where a Wilson’s Plover had decided to nest in the middle of the road.
I recorded 1,323 shorebirds of nineteen species. About a thirty percent drop from my last survey, three weeks ago. This is a typical shorebird population level for the refuge in mid-May.
Our wintering shorebirds are mostly gone. Almost 95% of the refuge’s Dunlins have left. At their peak in December, there were over three thousand Dunlins. On Friday I counted only 216.
Most of the shorebirds that you see at the refuge now are migrants in transit. It shows in the species mix from the survey, which included Wilson’s Phalarope, Spotted Sandpiper, White-rumped Sandpiper and Red Knot. All are species that are usually found at the refuge only in migration. The most common shorebirds on the refuge right now are breeding plumaged Semipalmated Sandpipers and Short-billed Dowitchers. They are also migrants moving up from their South American wintering grounds. Those Short-billed Dowitchers that are not in breeding plumage by now are non-breeding yearlings that will oversummer here.
In another few weeks, there may be only two or three hundred shorebirds left at the refuge. St. Marks has breeding Willets, Wilson’s Plovers, American Oystercatchers and Black-necked Stilts. Along with them will be yearlings of a half dozen species that did not migrate.
Shorebirds have a difficult time and some species have never completely recovered from the devastation of unrestricted commercial hunting at the end of the nineteenth century. There once may have been as many as five million Eskimo Curlews. They were a favored market bird, because of their taste and ease of shooting. At the end, as they became less plentiful, they sold for seventy-five cents a bird. They are now extinct.
Today, shorebirds are dealing with pesticides, climate change, loss of habitat and a developing avian flu pandemic. Many species have seen populations decrease by up to fifty percent in the last forty years. Yet they continue their journeys.
The Wilson’s Phalarope that I saw at the refuge on Friday may have spent the winter on a saline lake in the highlands of the central Andes. Things that represent serious obstacles for a human are of little import to a phalarope. They are undeterred by mountains, jungles or a Gulf crossing. They are not afraid of heights nor of the dark. Phalaropes regularly fly two miles up and undertake flights that continue through the night and can last for four days.
Spread your wings, break free and fly down to St. Marks. There’s still time to get in on shorebird migration this year.
Don Morrow can be reached at donaldcmorrow@gmail.com.