Loons: Gaviiformes

Physical characteristics: The common loon stands about 26.0 to 35.8 inches (66 to 91 centimeters) and weighs 5.5 to 13.4 pounds (2.5 to 6.1 kilograms). Underparts are white, upperparts are black with white checks and spots. The head is black, and the neck is black with white striping.

Geographic range: This species breeds throughout Alaska, Canada, northern New England, northern Midwest, and parts of Greenland and Iceland. It winters in the Pacific and Atlantic Oceans.

Habitat: Common loons breed in clear lakes and tundra ponds. The common loon winters mostly on coastal waters within 62 miles (100 kilometers) of shore. It also occasionally winters on inland lakes and rivers.

Diet: These birds eat mainly fish such as perch and bullhead as well as invertebrates such as snails and crayfish. They will eat vegetation when other food is scarce.

Common loons stretch, remove water, and signal with this motion. (© Gregory K. Scott/Photo Researchers, Inc. Reproduced by permission.)

Behavior and reproduction: During migration and winter, common loons are found in loose flocks or singly. They prefer large lakes because they require 100 to 650 feet (30 to 200 meters) for takeoff. Common loons are territorial on breeding grounds and will chase off intruders. Their call resembles a yodel, a series of repeated two-note phrases, and is used to defend territory.

Common loons nest farther south than other loons from May to October. They build their nests using vegetation at the edge of a lake. Two eggs are laid and incubated by both parents from twenty-seven to thirty days. Newborns can leave the nest at one day of age and are able to fly at eleven weeks. Chicks and eggs fall prey to gulls, crows, weasels, skunks, raccoons, and snapping turtles. Common loons live for up to thirty years in the wild.

Common loons and people: Human activity upsets the loon, and waterskiiers, boaters, and pets are taking their toll on the loon population. The increased number of houses being built along lakeshores is destroying loon habitat. Loons are also being found with alarmingly high mercury levels in their bodies. The mercury comes from lead fishing tackle as well as pollution.

Conservation status: The common loon is not threatened, though many conservation efforts are underway to keep populations stabilized. ∎