Common Loon

Common Loon

Gavia immer

Common Loon

The loon’s mournful cry is a beautiful and haunting symbol of northern waterways. The unusual cries,  varying from wails to tremolos to yodels, are distinct to individual birds, and can be heard at great distances. Loon cries are most prevalent during breeding season as pairs aggressively defend their territories. Native Americans believed it was “The Spirit of the Northern Waters,” and the French named it “The Diver with the Necklace.”


Common loons are migratory birds which breed in forested lakes and large ponds in northern North America and parts of Greenland and Iceland. They winter all along North America’s Pacific and Atlantic coasts as well as in Europe and Iceland. In eastern North America the common loon breeds from northern Canada south to New Hampshire, Vermont, and Massachusetts. They winter along the coast down to Florida and the Gulf of Mexico. Some loons may stay on Lake Champlain if there is open water.

Loons breed on lakes and deep ponds. They nest close to shorelines or on small islands Their nests are simple piles of vegetation or small depressions in the soil, which contain one or two eggs that range in color from pale olive to medium brown with darker spots. They incubate the eggs for 27 to 30 days. Hatchlings leave the nest on their first day and are able to fly in about eleven weeks.


Loons have striking red eyes, black heads and necks, and white striping, checkering, and spotting on their backs. They grow up to three feet (91 centimeters) with wingspans of 52-58 inches in length and weigh up to 12 pounds (5 kilograms). Loons have nearly solid bones and massive muscles; this makes it more efficient for them to dive under water than fly. In fact, they can dive over 200 feet (61 m.)  below the surface of the water in their search for food.

Loons are named for their clumsy, awkward appearance when walking on land, They eat mainly fish, although their diet can also include insects, crayfish, and some vegetation.

Threats to Loon Populations

In 1977, annual statewide surveys of the breeding status of the common loon in Vermont were begun by the Vermont Institute of Natural Science (VINS). The surveys have found that many lakes and ponds where common loons had bred in the past have been abandoned by breeding pairs.
Reasons for the vulnerability of the Vermont loon population include:

Water levels can affect loon nesting. Rising water can flood a nest. If the water level drops— caused by reservoir draw-downs for power, for example—loons may abandon their nest. Their legs are so far back on their bodies that they move awkwardly on land.

Human interference can cause nest abandonment. Boating or water skiing too close to a nest may cause the parents to desert a nest.

An alarming number of loons have died from lead poisoning after swallowing lead fishing sinkers and jigs lost by anglers.

Some loons have become entangled in fishing line left by anglers, with serious injury or death resulting.

Increased development along lake shores causes fewer desirable sites to be available for loon nesting.

Competition between loons for nesting sites.

Predation by birds like gulls, ravens, and crows, fish such as pike, and land mammals such as raccoons, weasels, and skunks.


How Can You Help the Common Loon?

Gavia immer English: Close-up of the head of a...

Keep at least 300′ distance from loon nests and nursery areas during the breeding season (May to August). Observe posted warning signs.

Keep a respectful distance from wild animals. Use binoculars.  If you hear a loon as you approach, back off immediately.

Don’t use toxic lead sinkers or fishing line.

Observe and report loon sightings and nesting activities.

Participate in the Vermont Loon Watch held annually on the third Saturday in July.

Binoculars (The-Lake-Life)
Bird Watching Binoculars Buying Guide (The-Lake-Life)
NH’s loons and another call for help (