Common Loon (Gavia immer)
Common Loons are hard to miss on Canadian lakes - if you don't spot these large tuxedo waterbirds in the middle of the lake, you are sure to hear its yodeling calls.
HOW TO IDENTIFY
Both male and female have a black head and bill and a black white checkered back and white ‘necklace’ around the throat. Common Loons are relatively large and swim low in the water, which helps distinguish them from other waterfowl.
Identify by Sound
Loons have 4 distinguished calls: tremolo, yodel, wail, and hoot. Each call has a distinct message. The tremolo is used when the loon is alarmed, or to announce its presence; the yodel is used by a male loon to announce and defend his territory; the wail is the 'marco polo' of the loon world; and hoots are used to keep in contact, such as between parents and chicks, or between mates.
BEHAVIORS
Common Loons spend a lot of their time working shallow waters for fish: swimming slowly and sticking their heads into the water to look for fish, then diving suddenly after their quarry with a quick plip! that hardly leaves a ripple on the water’s surface. Loons do all their feeding during the day, when they can best see their prey. At times, loons can be seen sticking one foot up out of the water and waggling it—this may be a means of cooling off, as scientists have observed loons waggling their feet more often on sunny, midsummer days. Loons also perform a territorial display of lifting their body upright and flapping their wings vigorously. Canoeists who get too close to a loon may witness this display, along with a defensive tremolo call as the loon swims away. Loons also tremolo when they fly from lake to lake or in circles above a lake, their necks sticking straight out and feet trailing behind them.
They can be very vocally active with nocturnal choruses. After sundown, many North Woods lakes reverberate with the echoes of loon wails and yodels and tremolos (which writer John McPhee called “the laugh of the deeply insane”). In spring, loon mates arrive back on their lake separately. Loons are monogamous, and pair bonds typically last about 5 years. If one year one of the mates doesn’t return, the other will quickly pair up with another mate. The male defines his territory through yodeling. Courtship consists of swimming in circles and synchronous dives. If nesting is successful, loon chicks can be seen going for a ride around the lake on a parent’s back.
WHERE TO FIND
Common loons are found throughout Canada, breeding on quiet, freshwater lakes 5–50 hectares in size. They inhabit lakes with an abundant supply of small fish. Loons are sensitive to human disturbance. Common loons migrate to warmer areas along the Pacific and Atlantic coasts and can be found on lakes, rivers, estuaries and coastlines.
SOCIAL LIFE
Loons are monogamous and typically stay together for about 5 years. Loon mates return to the same lake separately and if one doesn’t return, the other loon will find another mate. The male loon uses his yodel to define his territory and notify other loons to stay out.
Loons leave their chicks at about 12 weeks of age. The parents migrate, leaving the young to flock together to migrate a few weeks later. Juveniles overwinter on the coast, and stay there for 2 years. In year 3, they return north, but do not breed until they are about 6 years old.
NEST PLACEMENT
The male selects the nest site. Loons nest in quiet, protected, hidden spots of lakeshore, typically in the lee of islands or in a sheltered back bay. Loons can’t walk well on land, so nests are built close to a bank, often with a steep dropoff that allows the bird to approach the nest from underwater. They also use artificial nesting platforms, which people have offered as alternative habitat on lakes with extensive shoreline development. Many times a nesting pair of loons will reuse the same site the following year, refurbishing their old nest instead of building a new one.
NEST DESCRIPTION
Male and female build the nest together over the course of a week in May or early June, making a mound out of dead plant materials such as sedges and marsh grasses that grow along the lake’s edge. Then one of the loons crawls on top of the mound and shapes the interior to the contours of its body. The finished nest is about 22 inches wide and looks like a clump of dead grasses by the edge of the water.
FOOD CHAIN
Common Loons are expert anglers. Their diet consists of mostly fish, particularly perch and sunfish on their northern lakes. If fish are scarce or water is too murky for fishing, they will catch crustaceans, snails, leeches and even aquatic insect larvae. Though people on the surface only see loons disappear with a dive and reappear with a fish in their bill to be swallowed headfirst, their fishing pursuits underwater are something to behold. Loons shoot through the water like a torpedo, propelled by powerful thrusts of feet located near the rear of their body. When their quarry changes direction, loons can execute an abrupt flip-turn that would make Olympic swimmers jealous: they extend one foot laterally as a pivot brake and kick with the opposite foot to turn 180 degrees in a fraction of a second. In their wintering waters, loons eat smallish fish such as Atlantic croaker. Sometimes they band together in groups to chase schools of Gulf silversides.
The Common Loon swims underwater to catch fish, propelling itself with its feet. It swallows most of its prey underwater. The loon has sharp, rearward-pointing projections on the roof of its mouth and tongue that help it keep a firm hold on slippery fish.
Loons eat fish, frogs, crayfish and other aquatic animals.
Loons pack away a lot of fish! A loon family with 2 chicks can eat about a half-ton of fish over a 15-week period.
Loons spend almost all of their time in the water so do not have very many predators. Loon chicks are prey to large carnivorous fish, gulls, crows, and eagles.
FUN FACTS
Loons can live up to 15 - 30 years!
Loons have solid bones, unlike other birds, which make them less bouyant and better divers. When diving, they quickly blow air out of their lungs and flatten their feathers, making them super fast and efficient underwater. While diving, the loon's heart even slows down to conserve oxygen!
Loons need a long runway to build up enough speed for lift-off.
Loons are fast in the air too, flying at speeds near 112 km/hr!
how you can help
- Use steel fishing products instead of lead weights and hooks. Lead weights are easily lost and then consumed by fish and waterfowl. High levels of absorbed lead causes damage to vital organs and tissue. Fish and birds with lead poisoning become sick and easy prey. Lead poisoning works its way up the food chain and can be fatal to everything from fish, to loons, to bald eagles.
- Leave no trace. Abandoned or littered fishing line and hooks can also cause injury and death to loons when they become entangled in it.
- Give loons space when boating. Loons dive under water when approached by a boat, but commonly have young ones riding along on their backs. Loons and their chicks can be injured by boats and propellers.