The birds, being well-versed in Shakespeare, know that all the world’s a stage. Maybe not, but what they do know is that some of the world’s a staging area, and one of the most important staging areas is right here on the Cape and Islands. A staging area is a place where many birds go to rest and feed before or part way through a big migration. Now that breeding is over for most shorebirds and seabirds, they are pouring in from all over the northern hemisphere to spend late summer staging right here with us.
That’s why in mid-August, as birds of yards and woods go quiet, the birding action is more than ever concentrated at the beaches. Shorebirds mass on the flats and certain high tide roosting beaches, while terns and gulls crowd the beaches between their fishing sorties. Even wading birds, the herons and egrets, are staging here, with numbers in marshes and at roosts ticking up by the day. Birds and birders alike are here to revel in the piscine, benthic, and planktonic bounty of Cape Cod.
But today we talk terns. At places like Nauset Spit and Beach, Hatches Harbor, Sandy Neck, Monomoy, and other beaches you may see thousands of those delicate, diving cousins of gulls, the terns, gathered now in big roosts, mostly Common and Roseate Terns who breed locally in the huge, nationally significant Monomoy and Buzzard’s Bay colonies. But we know from banding studies of the federally Endangered Roseate Terns that, as with human tourists, birds from New York come up here to stage, and Canadian birds come down from up north.
The roseates are less common and can be hard to pick out, so listen for their distinctive two-note call, very different from the long, harsh calls of Common Terns. But these are not the only two species in a roost -also look for the odd Arctic Tern with their notably tiny legs, or Forster’s Terns, particularly common on marshy bay beaches, with their two black eyes – this mysterious species comes to stage here either from the Midwest, the southeast, or both. My favorites may be the Black Terns, a small tern of the interior - they nest in big freshwater marshes well north and west of here.
The same bait fish that bring the whales, Striped Bass, and oceanic seabirds like shearwaters from faraway places to summer here are what these traveling terns are after – sand lance, peanut bunker (as the fishing folk call tiny, young menhaden), young herring, and other small fish. The other reason is the number of relatively protected beaches on which to rest, though its increasingly difficult for them to find a place where people and dogs are not constantly flushing them, wasting that energy they were saving for a 3,000-mile flight to Brazil or West Africa. So if you see these big resting groups of terns and shorebirds, please give them a wide berth.
And while you’re out there, keep an eye out for some of these New York or Canadian staging terns in the coming weeks. There are subtle but definitive behavioral clues that separate them from the locally breeding terns. For example, the New York and Canadian terns will be the ones confusedly and haltingly circling the rotaries. Give these summer visitors a friendly Cape Cod beep and a wave to let them know you see them!
