Matinicus Rock, Part 1

(Be sure to also see Part Two of this post.)

I just returned from three weeks on Matinicus Rock, in Maine’s Penobscot Bay. About twenty miles off the coast of Rockland, the 23-acre Rock is home to a diverse array of breeding seabirds, including Atlantic Puffins, Razorbills, Black Guillemots, Arctic and Common Terns, and Leach’s Storm-Petrels. Matinicus Rock is also the only known breeding location of Manx Shearwater in the United States. I had the privilege of working with these species with others from the Project Puffin Seabird Restoration Program. It was a great experience.

Matinicus Rock is home to a historic 19th-century lighthouse and light tower, a boat house, and the one-room Audubon house. The house has no running water or plumbing–though, of course, there is a fast internet connection. Drinking water comes in jugs from the mainland, and there’s a rainwater cistern under the house for washing dishes, clothes and hands. Electricity good enough to power lights and small devices (no large refrigerators, for example) comes from a few solar panels out front. There’s a propane stove and small propane fridge. Oh, and the foghorn sounds every fifteen seconds and is loud enough to be heard for three miles.

The light house and light tower.

When I arrived on July 20th, tern work was starting to wind down. We stumbled across the occasional young chick, but the majority of the surviving progeny were approaching fledging age. Over 800 pairs of Arctic and 200 pairs of Common Terns were present on the island this year.

Common Tern. Notice the black-tipped long-ish bill, black cap with considerable white above gape, dark "wedge" in outer primaries due to molt, and lack of long tail streamers (all points to compare with Arctic).

Common Tern, again.

Commons also show a sizable black trailing underwing edge to the primaries.

When perched, the dark outer primary wedge is visible. One can easily see the newer, lighter inner primaries, and the older (4) outer primaries.

The size of the wedge can vary, though. This bird shows five dark outer primaries. Notice also the length of the tarsus (from the "knee" to the foot) on Common Tern.

Part of the tern work consisted of 3-hour feeding stints, during which we recorded all of the feedings that took place–including the time it occurred, the type and size of fish, which chick it was fed to, and which adult performed the feeding.

A tern plot. Each numbered stake corresponds to a nest, and (in most cases) a chick or two.

Common Tern carrying a mackerel.

Common Tern with a pollack.

Common Tern with a snipefish.

Common Tern with a sand lance.

Common Tern attempting to feed a butterfish--a fish that many chicks can't swallow. When butterfish makes up a large portion of tern diet, the chicks don't do very well.

Common Terns often dive-bombed us, while the Arctics were a bit less aggressive.

Arctic Tern. Notice the completely red bill, the smaller white space between cap and gape, and the long tail streamers.

Also notice the uniform upperwing on Arctic.

And, importantly, the thin trailing edge to the outer wing, instead of Common's thick edge.

Also see the short legs and the lack of newer primaries (Arctics always molt all their primaries before migrating north in spring).

Arctic Tern with a...larval lobster?

Juvenile Arctic Tern.

Young Arctics share the thin black trailing edge under the primaries.

And Arctic juveniles have light secondaries.

Common Tern juveniles are generally browner on top with more orange, larger bills, and darker secondaries.

(And, of course, the thicker dark trailing edge to the primaries.)

Also interesting were subadult terns. I noted a couple first-summer Arctic Terns (all in the inter-tidal zone), and several presumed second-summer Common Terns up in the colony, but I couldn’t confirm any were actually nesting.

First summer (second-year) Arctic Tern.

Apparent second-summer Common Tern--with white speckling in crown and remnants of a carpal bar.

A similar-aged Common Tern.

Another presumed second-summer Common with more white in the crown.

Sunsets on the Rock were spectacular, with each day a new variation.

Go to Part Two.

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