Common loon
The common loon is a notable aquatic bird known for its impressive diving abilities, capable of reaching depths of over 200 feet while hunting for fish and other aquatic prey. This species, the most prevalent of the four loon species in North America, boasts distinctive black plumage adorned with white spots and unique vertical stripes on its neck. Common loons are approximately 27 to 35 inches long and are recognized for their varied vocalizations, which include tremolos, yodels, and mournful cries, particularly during the breeding season. They typically inhabit freshwater lakes in northern forests during the summer and migrate south for the winter.
Nesting occurs close to water, often on islands or logs, where they build large nests from sticks and vegetation. Female common loons generally lay two eggs, and both parents share the responsibility of incubating and raising their young. While these birds face threats from human-induced environmental changes, such as pollution and habitat destruction, they also contend with natural predators. The average lifespan in the wild is around 9 years, although many can live significantly longer. Common loons are a unique part of their ecosystems, contributing to the biodiversity of their habitats.
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Common loon
The common loon is an aquatic bird that can dive to depths of 200 feet or more. Because of this, it is also called the great northern diver. It is the most common of the four species of loons in this family.
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Gaviiformes
Family: Gaviidae
Genus: Gavia
Species: Immer
Common loons are the most populous loon species in North America. They are known for their fantastic swimming and diving abilities. With webbed feet and slender, sleek bodies, they can quickly swim long distances underwater. Although they usually swim 13 to 33 feet (4 to 10 meters) deep, some common loons reach depths of 200 feet (61 meters) while catching fish. Dives last for several minutes. The loons can adjust their feathers and special air sacs to control how deep they dive.
Common loons make a range of sounds including tremolos, yodels, wails, clucks, mews, and cackles. In the breeding season, they have a high-pitched, loud, laughing sound that quivers between notes. Loons often make mournful, or sad-sounding, cries.
Common loons are fairly large, goose-sized birds that may be 27 1/2 to 35 1/2 inches (70 to 90 centimeters) long and weigh 56 1/3 to 282 ounces (1,600 to 8000 grams). Common loons have black plumage, or feathering, with white spots on their backs and wings and white on their underparts. The vertical, white stripes on their short necks have a different pattern from those of the other three species. In the winter they have gray feathers with lighter markings.
These aquatic birds have excellent vision for catching crustaceans, crayfish, shrimp, leeches, frogs, and fish. The fish are usually up to seven inches (15 centimeters) long, but some may be up to 16 inches (40 centimeters) long.
The greatest threats to common loons are human activities causing environmental changes. Pollution, like acid rain and oil spills, harm or destroy their habitats. Botulism, a form of food poisoning, may also be problematic. When water levels in their saltwater habitats drop drastically and rapidly, a tiny organism called a bacterium begins to live in and infect the decaying or dead plants and animals. Hot weather and shallow, still water cause the bacterium to grow faster. As the loons eat the infected plants or animals, they are poisoned and die. Water plants that grow too large and hinder their swimming and diving are also a problem. Natural predators of the loon include skunks, large birds, turtles, otters, and weasels. The average life span of the common loon in the wild is 9 years, but they may live for 15 to 25 years.
Male common loons help build the nests, often hidden but always very close to the water. Some nests are so close to or low in the water, they appear to float. These birds usually nest on islands, islets, or perches, like logs and rocks poking out of the water. The nest is a large pile of sticks, grass, reeds, and other materials. The pair usually nest alone and breed once each year. The female usually lays two brown or olive eggs with black spots. The male helps his mate incubate the eggs for one month until they hatch.
Both parents care for the chicks and feed them insects and small invertebrates (animals without backbones). Only young common loons can walk well on land. The chicks leave the nest soon after hatching with their parents and dive into the water. While brooding their chicks, loons often carry their young on their backs. Brooding means the parents protect the chicks and keep them warm by covering them with their wings and bodies. After two to three months, they can care for themselves and fly.
In the summer, common loons live on freshwater lakes in the northern forests of their range. They leave shortly before the lakes freeze and migrate south to spend the winter in warmer areas. In the spring, they often return to the same territories and nests.
Bibliography
"Common Loon." A-Z Animals, 28 May 2023, a-z-animals.com/animals/common-loon. Accessed 1 Apr. 2024.
Kirschbaum, Kari, and Roberto J. Rodriguez. "Gavia Immer." Animal Diversity Web, animaldiversity.org/accounts/Gavia‗immer. Accessed 1 Apr. 2024.