BIRDS OF NANTUCKET
by Kenneth Turner Blackshaw

Arctic Tern

ARCTIC TERN - THE DAYLIGHT BIRD

This bird knows 24 hours of daylight in summer and then 24 more in its 'other' summer. One text says they live eight months each year in areas where the sun doesn't set at all. You'd think they would get sunburned! But then, they are mostly white, so most of that light is just reflected.

We're talking about Sterna paradisaea, translating to the 'paradise' tern. I wandered into an amazing series of facts researching this name given by Erik Pontoppidan, the Bishop of Bergen, Norway, in the early 18th century. The word 'paradise' is fascinating, first used in the Greek 'Septuagint' describing the Garden of Eden. The Septuagint title refers to the legend that it took 72 Jews 72 days to do the original translation for Ptolemy the II of Egypt. But of course I digress. The Bishop felt that so beautiful a creature must live in a home beyond the sky.

And for this seabird, this is not such a great stretch. They nest all around the world in the northern hemisphere, as far north as dry land can be found. In the late 1800s, the Nantucket area, specifically the island of Muskeget, was known as the southernmost nesting place in North America.

Let's discuss a bit about what this bird looks like. We have four very similar terns on Nantucket: the Common, Roseate, Arctic and Forster's. Birders know these as medium-sized terns, MSTs. Fishermen often call them 'mackerel' gulls since they tend to hover over schools of small fish. These terns are smaller than gulls, with long, slim wings, and swallow-like tails. They fly gracefully with deep wingbeats, almost never soaring as gulls do. In the spring they all have black caps and are white below and light grey above.

To separate them it's best to get the bill color. In spring Arctic Terns have blood-red bills, all the way to the tip. But getting a good enough view to discern that can be a trick. If you come upon a group of terns sitting on a sandbar, as is often the case, look for ones that are sitting lower. Arctic Terns have shorter legs than the other MSTs. In flight, their wings are a more uniform grey. So at least in spring you have a hope of separating Arctic Terns from the others. In other seasons, that blood-red bill becomes black and you have to know which terns are likely to be where.

Actually Arctics are considered to be pelagic when not nesting. I remember dragging my seasick self on a too-small boat out to the Gulf Stream 70 miles east of the Georgia coast one late August. There we found Arctic Terns resting on bits of flotsam in the warm green waters, the only way to get that species on your 'Georgia' bird list.

These terns were just starting their long migration that would culminate in the waters off the Antarctic continent, 11,000 miles from their northern summer homes. Their annual trip is

conservatively estimated at 25,000 miles since

they do a circular route, down the east coast of South America, and then back up the west coast of Africa before arriving in our waters in early May.

Up until 20 years ago, they could be found nesting on Nantucket, along our more isolated beaches. Edith Andrews remembers seeing a 12- year-old that she had banded in the mid-'70s when there was a colony of them at Great Point. Arctic Terns have great longevity considering their arduous annual trip, one having made it to its 34th birthday.

Longevity was a real problem around 1900 since these birds' marvelous tail feathers made them a target for gunners who would pluck them and pass them on to ladies' hat manufacturers.

Although they no longer nest here, they are common nesters as close as Machias Seal Island in the Gulf of Maine. Years ago I was fortunate enough to go there to see the wonderful colony of Atlantic Puffins that live there. Arctic Terns were the dominant species and I was stunned at how aggressively they defended their territory. Being used to working in tern colonies, I was holding a stick above my head so they would strike that instead of my noggin. But Arctic Terns use a more effective weapon. I realized this suddenly when I felt warm liquid running down inside my ear and had an immediate desire to head for safer territory.

Not only do these terns travel 25,000 miles a year, they are excellent bombardiers as well. Unlike the Bishop of Bergen I wasn't thinking of paradise. I bet he was smart enough to stay out of

range! I

George C. West creates illustrations for these articles. If you enjoy 'social' birding, join the Nantucket Bird Club at 8 a.m. Sundays in front of Nantucket High School for a two to three hour birding trip. Call 228-1693 for more information. To hear about rare birds, or to leave a bird report call the Massachusetts Audubon hot line at 1- 781-259-8805. Ask Ken a question at: kenandcindy1@ comcast.net.