It’s summertime on the Cape’s beaches, which for me always brings to mind that famous old song about seabirds – Tern! Tern! Tern! At least I assume it’s about the seabirds – it’s by the Byrds, after all. In any case, early July is indeed tern time on the Cape, Coast, and Islands, when the diversity and abundance skyrockets for these more graceful cousins of gulls. While a week or two ago terns were all cloistered in their breeding colonies, often on remote islands, they are entering their post-breeding, wandering phase, which means we could now see terns from all sorts of far-flung locales on just about any beach.
Like gulls, shearwaters, cormorants, and petrels, terns are seabirds, not to be confused with “shorebirds,” which refers to sandpipers and plovers. Terns nest in noisy colonies at the coast or in big freshwater, interior wetlands, and all mainly plunge dive for small fish. Fourteen species of tern have been recorded on the Cape over the years, but some of those are rare, hurricane-blown waifs from warmer waters and other vagrants. Eight species occur regularly, three-and-a-half of them breed here. I say “and a half” because there is just one last Arctic Tern breeding in Massachusetts, where it pairs annually with a Common Tern – Arctic Terns have shifted their range significantly north since last century, leaving this one stubborn bird behind.
We host globally significant colonies of both Common Terns and federally Endangered Roseate Terns – about half the western North Atlantic population of Roseates nests on two islands in Buzzard’s Bay, and close to 15,000 pairs of Common Terns nest on Monomoy National Wildlife Refuge, making it the largest east coast colony. But these colonies are remote, and it is only now, when many birds are finishing up breeding, that we can see these species away from the colonies. Listen for the two-part call of a Roseate to find them among Commons now.
Tiny Least Terns are the species you are most likely to encounter May through August, as they nest alongside Piping Plovers on many of our busiest beaches. There, you can watch them noisily court mates, incubate eggs, feed their young, and drive away predators while you sip wine in your beach chair – all that’s missing is narration by David Attenborough. Overall, they are a delightful addition to any beach, but they do have an edge - get too close to the colony and they’ll poop on you with the accuracy of a smart bomb.
Several species are somewhere from rare to expected transients, including gull-sized Caspian Terns from the Great Lakes, ragged-crested Royal Terns from down south, and raccoon-eyed Forster’s Terns, who can be common around bayside marshes in late summer. But my favorite may be the Black Tern, a small, handsome species we mainly see as a southbound migrant. In breeding plumage, their front end is the color of an unlit charcoal briquette, while the back is the paler gray of coals ready for cooking. They nest in big freshwater marshes in North America and Eurasia, then winter on tropical coasts. Several have been reported from Tuckernuck to Wellfleet in the last few days.
Terns are tailor-made for tourist season on the Cape – they are a welcome sign of fish activity to a charter boat captain, an aerial accompaniment to the feeding humpbacks on your whale watch, or just an elegant bird improving the aesthetics of a beach just by loafing there. If you’ve never really looked at them, grab a bird book or fire up your apps and see how many different types you can notice this year.
I suppose you’re expecting some groan-worthy bird pun to end the report, but I’m not doing it this time. I’m really trying to tern over a new leaf.
