Common loon facts for kids

The common loon or great northern diver (Gavia immer) is a large bird from the loon family. These amazing birds are known for their beautiful calls and incredible diving skills.

When they are ready to breed, adult loons have a striking look. Their heads and necks are black with a shiny green, purple, or blue glow. Their backs are dark, and their bellies are pure white. When they are not breeding, they look brownish with a dark head and neck, and their bellies are whitish. Male and female loons look alike, but males are usually heavier.

During the breeding season, loons live on lakes and rivers in Canada, the northern United States (including Alaska), and parts of Greenland and Iceland. Some also breed in Svalbard and other Arctic areas. In winter, common loons fly to the coasts of the US (as far south as Mexico) and the Atlantic coast of Europe.

Loons eat many different animals, like fish, crabs, insect larvae, and snails. They usually swallow their food underwater, but they bring bigger items to the surface first. Loons are monogamous, meaning a male and female often stay together for many years, defending their territory and raising their young.

Both parents build a large nest from dead marsh grasses and other plants along the lake shores. They lay one or two olive-brown eggs with dark spots. Both parents take turns sitting on the eggs for about 28 days. The chicks are fed by both parents and can fly in 70 to 77 days. Loon chicks can dive underwater when they are just a few days old! They fly to their winter homes before the lakes freeze in the fall.

The common loon is considered a species of "least concern" by the IUCN Red List, which means it's not currently endangered. It's also the official bird of Ontario, Canada, and you can even see it on the Canadian one-dollar coin, called the "loonie"! In the United States, it's the state bird of Minnesota and appears on the Minnesota State Quarter.

About the Common Loon

The common loon is also known as the great northern diver, especially in Europe. It's one of five types of loons in the Gavia family. Its closest relative is the yellow-billed loon.

A Danish scientist named Morten Thrane Brünnich first described the common loon in 1764. The name Gavia comes from a Latin word for a seabird, and immer comes from a Norwegian name for the bird. The European name "diver" comes from how the bird catches fish by diving underwater. The North American name "loon" might come from an Old Norse word that sounds like its unique call.

What Does a Loon Look Like?

In flight

Adult common loons are quite large! They can be about 66 to 91 centimeters (26 to 36 inches) long and have a wingspan of 127 to 147 centimeters (50 to 58 inches). They usually weigh between 2.2 and 7.6 kilograms (4.9 to 16.8 pounds). Males are often heavier than females.

When breeding, loons have a broad black head and neck with a shiny green, purple, or blue color. Their eyes are red, and their bills are black. They have a special black ring around their neck and two white "necklaces" made of short streaks. Their backs are dark with small white spots, and their bellies are pure white. They have black and white patterns on their shoulders and a black tail.

Common loon taking flight

When not breeding, loons are brownish with a dark head and neck. Their eyes are surrounded by white, and their bill is mostly pale grey. Their bellies, lower face, chin, and throat are whitish.

Loons have a strong, dagger-like bill. They swim very low in the water, sometimes with only their head showing. To fly, they need a long "runway" on the water to gain speed. In the air, their head is slightly lower than their body, and their feet trail behind. Loons have solid bones, which makes them heavier but helps them dive deep underwater. Most birds have hollow bones to make them lighter for flying.

Juvenile swimming in the ocean off Mcgee Island, Maine

Young loons (juveniles) have a dark, brownish-grey head and back, with a white throat, cheeks, and belly. As they get older, they start to look more like adults.

Changing Feathers

Young loons keep their first set of feathers until January or February of the year after they hatch. Then, they slowly grow new feathers that look more like an adult's. Adult loons lose all their flight feathers at once around this time, which means they can't fly for a while! After this, they grow their beautiful breeding feathers.

Loon Genes

Scientists have studied the genes of common loons. They found that many of their genes are special and help loons with their unique lifestyle, like diving deep and flying long distances. These genes might help them use oxygen better, keep their bodies balanced, and even see well in low light underwater.

Where Do Loons Live?

Common loons mostly live in North America. They breed in the northern United States and Canada, as well as in parts of Greenland, Iceland, and Norway. They like large, deep lakes with clear water, where they can easily see and catch fish. They also prefer lakes with islands and coves to protect their nests from predators.

Most loons migrate, meaning they travel long distances. In North America, they spend winter along the Atlantic and Pacific coasts, sometimes stopping in the Great Lakes. They fly during the day, high in the sky. Some loons from Iceland, Greenland, and Canada fly across the Atlantic Ocean to winter along the coasts of Europe, from Finland to Portugal.

How Loons Behave

The common loon is an amazing fisher! It can dive as deep as 60 meters (200 feet) to catch its prey. With its large webbed feet, it's a very fast and skilled underwater hunter. Because their legs are set far back on their bodies, loons are clumsy on land. They slide on their bellies and push themselves forward with their legs. But in the water, they are graceful swimmers and divers, and they can fly for hundreds of kilometers during migration. When flying, they often make a special call that helps identify them. They can fly as fast as 120 kilometers per hour (75 miles per hour)!

What Do Loons Eat?

Foraging

Fish make up about 80% of a loon's diet. They eat fish up to 26 centimeters (10 inches) long, including minnows, suckers, pike, perch, trout, and bass. Young loons usually eat small minnows and sometimes insects. If fish are hard to find, loons will also eat crabs, crayfish, snails, leeches, insect larvae, frogs, and even some aquatic plants. They have even been known to eat ducklings!

Loons use their strong back legs to push themselves through the water at high speed to catch their prey. They are visual hunters, so clear water is very important for them. They usually dive 4 to 10 meters (13 to 33 feet) deep, but they can go much deeper. On average, a dive lasts about 42 seconds, but they can stay underwater for about a minute.

Raising a Family

On a nest by water in Maine, U.S.

Common loons are usually monogamous, meaning a male and female stay together for many years to breed. They defend a territory that might be a whole small lake or a protected part of a large lake. If one loon dies or is forced out of the territory by another loon, the remaining loon will find a new mate.

Loons don't stay together during winter. In spring, the males usually arrive at the breeding lakes a few days or weeks before the females, as soon as the ice melts. They build their nests on shore, often where they will lay their eggs. The nest is about 56 centimeters (22 inches) wide and made of dead marsh grasses and other plants. After about a week of building, one parent shapes the inside of the nest with its body. About 40% of nests are successful in hatching chicks, and most young loons survive thanks to their parents' care.

Egg

Eggs are usually laid in May or early June, depending on when the ice melts. A pair usually lays two (sometimes one) olive-brown eggs with dark spots. Both parents take turns incubating the eggs for about 28 days. Loons often build nests along steep lake shores so they can quickly dive into the water if a predator comes near.

Newborn chicks are dark chocolate brown with white bellies. Within hours of hatching, they leave the nest with their parents, swimming close by and sometimes riding on a parent's back. Parents and chicks often stay in shallow, quiet bays where the parents can protect them from other loons and eagles, which are their main predators. Chicks can make shallow dives from their first day and dive deeper as they grow. They can fly after 70 to 77 days. Both parents feed the chicks live prey until they can fly. As they get older, chicks catch more of their own food, but they might still beg from their parents for a while. Young loons leave the breeding grounds before the ice forms in the fall, a few weeks after their parents.

Choosing a Home

Loons tend to choose breeding lakes that are similar to the lake where they were born. This is called "natal habitat imprinting." It's a bit of a mystery because loons born on small, acidic lakes (which are not as good for raising chicks) still prefer those types of lakes when they grow up.

Loon Calls

The common loon makes many different sounds, each with its own meaning. The most common calls are the tremolo, the yodel, the wail, and the hoot. They call more often at night than during the day, and more often when it's cold or not raining much.

• Tremolo: This call sounds like a short, wavering laugh. Loons use it when they are stressed or alarmed, like during fights over territory or when they feel threatened. It's also the only call they use while flying, to let other loons know they are there.
• Yodel: Only male loons make this long, complex call. It's used to mark their territory and during fights with other loons. The longer the yodel, the more aggressive the loon is. The sounds in the yodel can even tell you how big and healthy a male loon is!
• Wail: This is a long call with up to three notes, often compared to a wolf's howl. Loons use it to tell other loons where they are. Breeding pairs or a parent and chick might use it to stay in touch or move closer together.
• Hoot: This is a short, soft call, used for close contact. It's a more personal call than the wail and is used only within small family groups or flocks. Loons hoot to let others know where they are, and parents often hoot to call their chicks for feeding.

How Long Do Loons Live?

Common loons can live a long time! Many loons live over 20 years. Scientists have found that loons usually survive well until they are in their mid-20s. However, male loons around 15 years old might start to have more trouble, losing their territories or being less healthy. When this happens, older males might become more aggressive and vocal, trying extra hard to breed for another year or two before they die.

Who Hunts Loons?

Adult common loons don't have many predators. Bald eagles might attack loons on their nests, and sharks have been known to attack them in winter. If a predator comes near, a loon might attack it by rushing and trying to stab it with its sharp bill. They aim for the predator's belly or the back of its head, which can be deadly for animals like foxes or raccoons.

Loon eggs are eaten by many mammals, including American mink, striped skunk, otters, foxes, and raccoons. Birds like herring gulls, ravens, and American crows will eat eggs if the adult loon leaves the nest. Because their nests are right at the water's edge, loon eggs are very vulnerable if the parents are not there.

Loon chicks can be killed by common snapping turtles, large gulls, bald eagles, and big fish like northern pike. Eagles are a particularly big threat to young chicks.

Loons can also get sick from tiny parasites like worms and other germs. Sometimes, eating infected fish can lead to a sickness called botulism, which can cause paralysis and drowning.

Loon Conservation

Since 1998, the common loon has been listed as a species of "least concern" on the IUCN Red List. This means it's not considered endangered because it lives in a very large area and its population is stable. There are estimated to be over 600,000 common loons in the world.

The common loon is protected by several international agreements, like the Convention on the Conservation of Migratory Species. In the United States, the United States Forest Service considers the common loon a species that needs special attention due to threats in its habitat.

Threats to Loons

One of the biggest threats to common loons is pollution from mercury and acid rain. When fossil fuels are burned, they release mercury and other chemicals that cause acid rain. These pollutants travel in the air and fall into lakes, especially in the eastern parts of the US and Canada.

Acid rain makes lakes more acidic, which can reduce important nutrients and increase harmful metals like mercury and lead. Mercury turns into a very dangerous form called methylmercury in water. This methylmercury then moves up the food chain, from tiny creatures to fish, and then to loons. Loons at the top of the food chain get the highest levels of mercury. Male loons often have more mercury because they eat bigger fish. Female loons can pass some mercury into their eggs, which helps them but can harm their chicks. Young loons have the lowest mercury levels, and their levels can help scientists understand how much mercury is in a lake.

High levels of mercury can harm loons' health and make it harder for them to have chicks. Studies have shown that if female loons have too much mercury, their chances of successfully raising chicks drop a lot, and sometimes they can't have any chicks at all. Acidic lakes also lead to fewer successful broods. Even though efforts have been made to reduce acid rain, climate change (like warmer summers and droughts) can still make lakes more acidic and make it harder for fish to return.

The common loon's breeding range has also moved northward. A century ago, they bred as far south as Iowa. Besides pollution, loons are also threatened by:

• Lead poisoning: From fishing sinkers that they might swallow.
• Hunting and predators: Though adult loons have few predators, their eggs and chicks are vulnerable.
• Water-level changes: Flooding or changes in water levels from dams can harm nests.
• Shoreline development: Loons abandon lakes if there's too much building along the shore.
• Boats: Personal watercraft and powerboats can drown chicks, wash away eggs, or swamp nests.
• Oil spills: The common loon is still considered an "injured" species in Alaska because of the Exxon Valdez oil spill.

To help loons, some environmental groups put out floating nesting platforms on lakes. These platforms help protect nests from predators and changing water levels.

Loons in Culture

Cassell's book of birds, ca 1875

The common loon's voice and appearance have made it important in many Native American stories. For example, the Ojibwe people have a story about a loon that helped create the world. The Mi'kmaq people tell a story about Kwee-moo, a loon who was a special messenger for their hero, Glooscap. Many stories from the Pacific Coast peoples tell the tale of the loon's necklace.

Old folk names for the common loon include "hell-diver," "greenhead," and "call-up-a-storm," because its loud cries were thought to predict stormy weather.

In the past, people in the Scottish Islands ate common loons until the 1700s. Their thick layer of fat was even used as a medicine for leg pain!

As mentioned, the common loon is on Canadian money, including the one-dollar "loonie" coin and old $20 bills. It's the official bird of Ontario and the state bird of Minnesota. The soccer team Minnesota United FC even uses the loon in its logo!

The loon's wailing call is often used in movies and TV shows to create a feeling of wilderness or suspense.

The common loon is a main character in the children's book Great Northern? by Arthur Ransome. In the story, children on holiday in Scotland find a pair of loons nesting, which is very rare for that area. They ask an ornithologist (bird scientist) for help, but he turns out to be an egg collector who wants to steal the eggs and kill the birds. Luckily, the children manage to protect the loons.

In the 2016 Pixar movie Finding Dory, a somewhat messy and silly loon named Becky helps the characters Nemo and Marlin get into a marine life institute.

Loons are also featured a lot in the 1981 movie On Golden Pond.

Images for kids

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  Common loon stretching

See also

In Spanish: Colimbo grande para niños