Last week, I spent five days on the coast of Maine at the Audubon Camp on Hog Island. One day, our group headed out on the camp’s modified fishing boat for a daylong cruise on Muscongus Bay with a north wind to clear the skies and flatten the water, a perfect day to look for seabirds. The camp instructors on board were ornithologists Peter Vickery, co-author of A Birder’s Guide to Maine, and Steve Kress, director of the Audubon camp and director of Project Puffin and the Maine Seabird Restoration Project.

Our destination was Eastern Egg Rock, a nesting island for Atlantic puffins and three species of terns. Along the way, while our instructors prepared us for the birds we would see, we looked at nesting cormorants, harbor seals, harbor porpoise, gannets, and a huge eagle nest with two chicks in it.

Puffins are easy to identify. Only about a foot long, they are black on the back and white on the front, and during the breeding season they have a very large multi-colored bill. The bill is covered with a thin sheath of keratin, the same stuff that gives structure to hair and fingernails, and as the bird ages its bill adds a few more grooves and more color. We had seen pictures of puffins holding multiple slippery fish crosswise in their bills, and wondered how they held them there while diving to catch more. The answer is that they have serrations on the tongue, which prevent fish from slipping out.

Historically, puffins nested on several of Maine’s outer islands, but by 1855 the population had been wiped out by hunters and egg gatherers. In 1973, Steve Kress headed up an effort to begin transporting puffin chicks from a nesting colony on Newfoundland to Eastern Egg Rock, where they were raised in artificial nest burrows until they were old enough to fly. They continued to transplant chicks every year, and in 1977 the first of those birds returned to Eastern Egg Rock to nest. Last year, 123 pairs of puffins nested there. Puffins can live 30 years or more, do not breed until they are four or five years old, and produce only a single egg each year. Since the beginning of Project Puffin, interns have camped on the island for the entire breeding season to monitor the birds and protect them from predators.

Atlantic puffins have been studied intensively on their breeding islands, but up to now no one has known where they go in the winter. Last year, for the first time, Project Puffin staff attached tiny transmitters to some of the puffins to track their winter movements. At first, only a few birds were fitted with these very expensive electronic gadgets, but a few more will get them this year, and it is hoped that within a few years enough valuable information will have been collected to unravel the mystery.

We arrived at Eastern Egg Rock, a small, treeless, rocky island, and our boat circled it slowly to give us excellent looks at the birds. Puffins perched on rocks, floated on the water, and flew past the boat, looking like little footballs with wings. We even heard the male’s call, a low squeaky growl. There were also laughing gulls on the island, and a couple of razorbills, elegant looking members of the auk family. Three species of terns flew around us, and we frantically tried to remember the identification tips we had recently learned. The Arctic tern, who makes the longest migration of any bird in the world, looks neck-less in the air, and has a crisp black line along the trailing edge of the wing. Common terns appear in flight to have a neck, but the dark line edging the wing looks smudgy. The endangered roseate terns look ghostly white in the air, and their shorter wings flap faster, giving them a fluttery look.

The air around us was crowded with terns, and they moved so fast it was nearly impossible to focus on one bird long enough to see any field marks. Finally I gave up, put my binoculars down, and just enjoyed the spectacle of all those magnificent, graceful birds swirling over the ocean and the island on a clear sunny day.

Hardy Boat Cruises of New Harbor (www.hardyboat.com) runs Puffin Watch cruises to Eastern Egg Rock through August, narrated by an Audubon naturalist.