Birds should know better than to put all their eggs in one basket. But that’s what most seabirds do. There are roughly 4,600 coastal Maine islands. Only about 6 percent of them are suitable for significant nesting. Even fewer support a wide variety of nesting birds. Merely one-tenth of 1 percent support breeding Atlantic puffins, and that’s if you count the disputed Machias Seal Island, which is claimed by both the United States and Canada.
I know this is obvious, but bear with me. Birds of the ocean are not happy on land. Many come ashore just long enough to breed, and then skedaddle back to sea at their first opportunity. If they could lay an egg on water, they would. Some of our islands are essential to seabird survival.
Almost all seabirds are colonial nesters, taking advantage of safety in numbers. Acrobatic birds, such as terns, are capable of mobbing intruders and forcing them away from nests. Other, less agile seabirds, often chose to nest with terns, letting them do all the dirty work. That’s one reason Maine’s five puffin colonies are also tern colonies.
From there, the needs of various species diverge. Each has different nesting requirements. Even among terns, our common and arctic terns nest in the open, on barely noticeable scrapes in the soil. But the roseate terns prefer cover, and will only nest on islands that have enough thick scrub to shelter and hide them.
Each member of the puffin family has its own nesting needs. Atlantic puffins burrow deep into the crevices between rocks, digging up the soil and tossing it aside. Razorbills also push their way down into the gaps between boulders, though not as deeply as the puffins. Common murres lay their eggs on bare rock, right on the open edges of cliffs. Their eggs are oblong so that they won’t just roll off the precipice. Black guillemots are crevice nesters, but they can tolerate nesting on the mainland, generally in rocky cliffs that discourage four-footed predators.
Often the major nesting islands are far enough offshore that they are not easily visited by hawks and owls. Three of our five puffin islands are at least nine miles out to sea — a distance that certainly discourages owls and makes the eagles think twice. Terns will nest closer to the mainland because of their ability to defend their nests from hawks. They are more vulnerable to owl predation, and it’s not unusual for a great horned owl to fly out to a tern colony for a midnight snack. But in that case, the terns are hoping that the owl will choose another victim. In a colony of 500 terns, your chances of becoming owl food on any given night are pretty slim. Plus, on many nights, coastal fog can convince the owls to forgo seafood.
Thus, over time, seabirds have settled on just a handful of islands that meet their qualifications. For millennia, the strategy worked well. Then the Europeans arrived. During the sailing era, hunting and egg gathering collapsed many populations. Some birds, such as the flightless great auk and the Labrador duck, went extinct almost immediately. In the early 1900s, the fashion industry slaughtered countless more. Today, oil spills, recreational visitation, introduced predators and a host of human-caused threats put the remaining colonies in peril. Our seabirds need friends.
And they have them. The Canadian government maintains lighthouse keepers and scientists on Machias Seal Island. In southern Maine, Eastern Egg Rock is owned by the state; National Audubon’s Puffin Project provides oversight. For the rest, the Maine Coastal Islands National Wildlife Refuge is responsible for stewardship on 58 islands, including eight that are seabird restoration projects and three that have puffins: Matinicus Rock, Seal Island, and Petit Manan. The refuge stretches 250 miles down the coast. On an impossibly tight budget, the U.S. Fish and Wildlife Service can do little more than post up warning signs on these islands, but they, too, have friends. A nonprofit group called Friends of Maine’s Seabird Islands fills the gap, linking scientists, volunteers, partners and businesses to this prodigious conservation effort. See maineseabirds.org.
If you ever wondered how a small group of dedicated citizens can both protect the environment and improve the economy, consider this: Up to 7,500 tourists visit the islands, using the services of more than a hundred Maine companies, boosting the economy by up to $10 million a year. And that doesn’t even count all those puffin souvenirs.
Bob Duchesne serves as a Maine Audubon trustee and vice president of its Penobscot Valley Chapter. Bob developed the Maine Birding Trail, with information at www.mainebirdingtrail.com. Bob can be reached at firstname.lastname@example.org.