Loons are aquatic birds known as excellent divers and can dive to depths of 60m (200 feet). They can keep submerged for as long as several minutes, although most dives last up to a minute.
There are five species of loons and all can be found in North America. These are the red-throated loon, Pacific loon, common loon, yellow-billed loon, and Arctic loon.
The position of their legs makes them excellent swimmers, and their webbed feet are used as paddles. Diving is propelled by their feet only, although they will occasionally use their wings to maneuver.
Loons can change their specific gravity so that they can swim low in the water. This is achieved by expelling air from their lungs and through compression of their plumage.
Loons feed on fish, and their bills are excellent for this. A loons bill is shaped differently from ducks or geese. Their bills are sharply-pointed and are never hooked at the tip.
Loons spend their time on the water; in summer they spend time on lakes, and in winter they prefer coastal waters.
Due to their legs, which are set back on their body, they are not suited for life on land and have trouble standing. Moving around on land, they either push themselves along on their breast or are semi-erect.
Loons have plumage that is waterproof and insulating to allow them to stay in the water.
Modern loons are much smaller than their ancestors which stood up to 2 meters tall in the Upper Cretaceous period. However, they still have a strong resemblance to the toothed Hesperonis regalis, a large-toothed bird.
Loons can fly, although most species cannot take off from land. They generally need a long lake to take off, but once in the air can fly at speeds of 110 km/h (70mph). Loons cannot fly all year, however, and after molting their flight feathers, they become flightless.
The red-throated loon is the smallest of all species of loon measuring 21-23 inches (53-58 cm). They get their name from their rusty-red neck. The red-throated loon is the only loon that does not have the checkerboard back in summer. They have a gray head with a stiped hind neck and nape. During the winter, the red-throated loon is noticeably grayer than other species of loons. Their bill is held uptilted.
The red-throated loon can be found along coastal and tundra in the north as high as Alaska, and spend the winter southward along both the Pacific and Atlantic coasts. They can also be seen along the southern shores of the Great Lakes. In summer they breed on small lakes and feed on larger lakes or at sea.
The red-throated loon generally gives birth to 2 olive-brown eggs, speckled brown or black. Their nest is made of vegetation. Both the male and female share incubation duties which last from 24 to 29 days.
The red-throated loon can be seen on smaller areas of water due to its short take-off.
The red-throated loon can be heard cackling and wailing.
The Pacific loon measures between 23-27 inches (58-68 cm). Like all other species except the red-throated loon, the Pacific loon has a chequered back. They have a striped neck, a black throat, and a gray crown. In winter their crown becomes darker and extends further down the sides of the face below the eye. They are the darkest of all species of loons in winter. Unlike the common loon in winter, the Pacific loon has a white patch on their fear flank.
The Pacific loon can be found through Alaska, preferring to winter along the Pacific coast of North America. During the summer they can be found in large lakes.
They breed between May and June, laying 2 olive-brown eggs spotted with black. Their nests consist of a mass of vegetation that can be found close to the edge of the water. Their nests are distinguishable by rising out of the water. Incubation is shared by both the male and female for 29 days.
The Pacific loon makes a sound like a loud wailing.
The common loon is a duck-like bird that measures between 27-32 inches (68-81 cm). They have a checkered back but can be identified by their black head in summer which has a greenish gloss. During the winter, their back changes to a barred gray, with tips of gray. Their bill is black and is held horizontally. In winter, the white from their neck can extend above the eye.
The common loon prefers lakes in summer where they breed between May and June. They take to coastal waters in winter. They spend their winters on both coasts in Canada and the United States, extending down to the Gulf coast.
Both parents share time looking after the eggs incubating which takes up to 29 days. They usually have 2 olive eggs with brown spots. Nests are usually made close to the shore, although they can also lay their eggs on bare ground.
The common loon is not a colonial bird and a lake is usually home to one pair. Large lakes may have two or more pairs.
The common loon can be heard especially during the summer. They make a wailing cry sound that is resonant. They have been described as maniacal, thrilling, and blood-curdling. They have a laughing tremolo, a yodel, and a wail.
The yellow-billed loon is the only loon with a yellow beak and can be easily recognized with this one feature. Although they are slightly larger than the common loon at 33-39 inches (84-99 cm), their yellow bill identifies them throughout the year. Their bill is large and looks uptilted, although it is the lower part that upwards-angled
As with most other species of loon, they have a checkered back in summer, but in winter have a gray, barred back. Their head has a purplish gloss, with white patches on their throat and sides of the neck.
The yellow-billed loon can be found on tundra freshwater lakes, ponds, and rivers in summer, and in more coastal areas such as bays and inlets in winter. They breed in the Canadian arctic before heading down through Alaska onto the west coast of Canada in the winter.
The yellow-billed loon can be found in more northern regions than the common loon, with very little overlap in their ranges.
The incubation period lasts between 27 to 29 days and both the male and female look after the eggs. They generally lay 2 eggs, which are brownish-olive and spotted with brown.
The Arctic loon looks similar to the common loon but they have a gray crown and hindneck. They also have long white streaks down their neck and are slightly smaller. In winter they become darker, with a dark gray above and white underparts. They have a straight bill.
The Arctic loon can be found in summer frequenting freshwater lakes, both inland and near the coast. They can be found from Alaska and across east into Canada. They can be found in winter mainly along the Pacific coast, down as far as Baja California.
Their incubation period lasts about 29 days and lay two greenish-olive eggs with black spots. They build their nests from a mass of vegetation and mud close to the shore.
The Arctic loon can be heard making many different sounds. These can include croaks, growls, yelps, and long wailing noise. A kwuk-kwuk-kwuk can be heard during flight.