Birds don’t just leave in the fall, they arrive, too. Many birds migrate from Labrador, the Gaspe Peninsula in Quebec, and other points north to spend the winter in sunny, warm Maine. Everything is relative.

A dozen Barrow’s goldeneyes, a duck species, splashed down in the Penobscot River last weekend. They are handsome and uncommon ducks, the males in bold black-and-white patterns, the females in discreet brown and gray. Both have yellow eyes, hence their name.

They will spend part of the winter in the moving water of the river, diving to the bottom to find insect larvae, snails, clams, fish eggs, worms and other small items.

When the Penobscot freezes over, they move to salt water.

There is teeming life under and between the rocks on the river bottom all winter. The water is well-oxygenated from tossing over rocks, and is full of nutrients from fallen leaves upstream. Diving to the bottom, the ducks poke between the rocks and find larvae or nymphs of insects, such as stoneflies, mayflies, dragonflies, dobsonflies, crane flies, riffle beetles and damselflies, of all sizes and shapes.

The ducks’ rich food, their layer of fat, their inner down feathers and outer waterproof feathers keep them warm as they dive again and again into the icy Penobscot. As winter progresses, they occasionally will explore the ice-free parts of the Kenduskeag Stream, and also fly to salt water. In mid-March, off they go, back to their nesting grounds.

Barrow’s goldeneyes are never common in the East. There are many more that nest in the Rocky Mountains in the West, and winter along the Pacific Coast. The Maine wintering population is very small, probably fewer than 200. Eastern birders from south of Maine come to Bangor in the winter just to see them. Belfast Harbor and from Bangor to Old Town are the best places to find them.

It is thought that “our” wintering Barrow’s goldeneyes came from a small population recently discovered nesting in Quebec’s Laurentian Highlands.

They nest in hollow trees alongside lakes. The young hatch and soon afterwards, climb or jump out from the nest and land on the ground. They make their way, led by their mother, to a nearby lake. Their mother leads them to food-rich areas around the lake, and the young hone their food-finding and catching skills. They grow fast. The little “tabs” on their backs morph into wings.

And now at last, they are here. The late Inez Boyd, who took much joy in birds and birding, said, “It’s not enough just to know they’re here. You want to be right out there on the welcoming committee.”

For information on the Fields Pond Audubon Center, call 989-2591.