Loon Research by Maine Students

Common Loons, Gavia immer: Research by Maine Students

By Jandee Ferland, Rachel Gosselin and Sarah Clark Vassalboro Community School Vassalboro, Maine E-mail: sueme50@aol.com

Common loons are also called great Northern divers. They are found in the Northern United States as far as the Arctic Circle. In the summer it makes its home in freshwater lakes and ponds.

MIGRATION Most loons migrate to the Atlantic, Gulf, or Pacific coasts of North America although a few stubborn birds stay on large lakes. Based on records loons return to the same lakes each year. However, mates usually don't winter or migrate together but return to the same lake independently,

LIFE CYCLE The loon life cycle is very interesting. Loons live for about 10 - 15 years, although a lucky loon may live as long as 30 or more years.

Nesting A nesting pair of loons take up some some space on the water. A nesting pair needs a lake about 10 -15 acres. In addition to lake size, shoreline shape often determines how many loons can live on 1 lake. A loon nest is made up of things like dead grass and other organic debris found around the nest site and is simply a hollowed out, shallow depression one or two feet in diameter. Most loons' nests have 2 eggs. Some nests have 1 or rarely 3 eggs. Loons may lay a second set of eggs if the first nest is destroyed. Loon eggs are somewhat 3" by 2" with a thick outside and are olive green with dark spots.

Care For Eggs and Young Have you ever asked yourself which parent incubates the eggs and how long do they take to hatch? Well, I know the answer to that question. Both male and female take turns incubating the eggs which takes 26-31 days to hatch. The eggs hatch about a day apart.

There are several reasons that chicks ride on their parents backs. One is they are safe from enemies, conserve energy and stay warm. Chicks ride on their parents back during the first 3 months of life.

It takes a while to reach adulthood. Loons do not aquire full breeding plumage until about 3 years of age. Current data suggests that most immature birds stay on the ocean for about 3 years before returning to nest on the northern lakes.

LOON CALLS The common loons have 4 different main calls. They are the wail, tremolo, yodel and the hoot.

1) The wail sounds like a wolf howl. Individuals use this call to find their mates and chicks.

2) The tremolo call sounds like a trembling laugh. It is normally used when loons are disturbed. It is also the only call they use while they are flying.

3) Yodel is also a call. It is a sustained call made up of several of the same three syllable squeals. It is an aggressive call generally given in territorial confrontations by male loons. Each male has an individual yodel. Only the male yodels, so that is one way to tell males from females.

4) The hoot is a soft,one-note call loons close quarters. The hoot is hardly heard by humans.

Chicks also have a call. It is a high-pitched call that sounds like "a-wheet-wheet-wheet". It is usually used when they' re begging for food.

IDENTIFICATION Loons are called primitive birds because loons are relatives to dinosaurs. They have been around about 25 million years.

Loons are 36 inches long. Their backs and wings are black with white spots. The head and neck are shinging black and green, and the neck has white lines and the eyes are red. The webbed feet are also black and the tails are short. Their feet are set back on their bodies for swimming so they have trouble walking on land. They eat chiefly fish, and they prefer 3"-8" yellow perch.

There are many kinds of loons, Common Loons, Arctic Loons, Pacific Loons, Red- throughted Loons, and Yellow billed Loons. The loon is the state bird of Minnesota. Loons can hardly walk on land but they can run acros the water really fast.

By Jandee Ferland, Rachel Gosselin and Sarah Clark Vassalboro Community School Vassalboro, Maine E-mail: sueme50@aol.com

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