Sanderling (Calidris alba)
By Rhiannon Thunell
Head to the beach on Lake Michigan in late summer and you will almost certainly spot small shorebirds rushing up and down the beach and back and forth with the waves. I have watched these tiny birds for hours as they chase the waves, moving so fast that their legs seem like a blur. This is the Sanderling, the tiny shorebird which always seems to be in a hurry. They are in a hurry for a reason. Sand crabs and other invertebrates are the Sanderling’s favorite food sources. They are easiest to spot just after a wave passes. This is why the Sanderlings “chase” the waves on the beaches.
Sanderlings only visit Indiana for a short while. They do not nest in our state, nor do they winter here. They will nest in the high arctic of North America, Europe, and Asia, laying 3 or 4 eggs in nothing more than a scrape on the ground. While they are on their nesting grounds, Sanderlings will eat insects and even some plant matter. They may form either a monogamous or a polyandrous pair bond, incubating the eggs for 24-31 days. The chicks will fledge in just 17 days and the birds that fledge in North America fly to the beaches of South America for the winter, with some flying all the way to the southern tip of the continent. The Sanderling has two distinct subspecies: C. c. alba, which breeds on Ellesmere Island, Greenland, Svalbard, Franz Josef Land and the Taymyr Peninsula; and C. a. rubida, which breeds in northeast Siberia, Alaska, and Canada. Sanderlings are still fairly common in the Americas, but some studies have shown declines of up to 80 percent since the early 1970s. Their Arctic breeding grounds are under threat from warming temperatures, while their South American wintering grounds are threatened by coastal development and oil spills.
My favorite place to photograph Sanderlings is on the break wall at Michigan City Beach. On the path out to the lighthouse, it’s easy to find a cooperative Sanderling to photograph, often accompanied by other birds such as Semipalmated Sandpipers. I once observed a Sanderling picking at the carcass of a large salamander there, which is a behavior I have not seen anywhere else.
Everyone can enjoy watching Sanderlings on the beach. Whether you are a birder or not, the next time you are on the beach you should take some extra time to watch them. They are always entertaining in their constant mission to find food every moment the waves retreat from the sand.