Great Northern Loon

From SongbirdReMixWiki

Jump to: navigation, search


Common Name: Great Northern Loon
Scientific Name: Gavia immer

Size: 47-39 inches (61-100 cm); Wingspan: 48-60 inches (122-152 cm)

Habitat: Northern Hemisphere; breeds in much of Canada and Alaska, parts of northern United States, southern parts of Greenland to Denmark and in Iceland. It winters on sea coasts or on larger lakes over a much wider area including the Atlantic coast of Europe from Finland to Portugal and the western Mediterranean, the Atlantic coast of North America down to northern Mexico, and the Pacific coast of North America from northern Mexico to the tip of Alaska.

Loons breeds on large, deep freshwater lakes in coniferous forest or on open tundra, requiring clear water with visibilities of at least 3-4 m and small islands (less than 2.5 ha) for nesting. Non-breeding It winters along the coast on exposed rocky shores, sheltered bays, channels and sheltered inlets showing a preference for shallow inshore waters. They may also be found inland on lakes and reservoirs during this season, although this is largely influenced by the weather.

This species is strongly migratory, with inland breeding populations moving south or to the coast after breeding. The species breeds from May onwards in isolated solitary pairs, nesting later further to the north depending on the timing of the thaw. Adults become flightless for a short time in late-winter when they molt their flight feathers. During the winter the species occurs singly, in pairs or in small loose flocks in marine habitats, occasionally also forming large congregations of about 300 birds.

Status: Least Concern. Global population: Unknown amount of adult individuals. The overall population trend is decreasing, although some populations have unknown trends. When breeding the species is threatened by fluctuating water levels due to the building of dams, acidification of breeding lakes, heavy metal pollution due to industrial run-off and lead poisoning from ingested lead fishing weights. It is also highly sensitive to human disturbance such as shoreline development and human, and may desert lakes after increases in human presence and. During the winter the species is highly vulnerable to coastal oil spills, especially in areas where large congregations form, and entanglement in monofilament fishing lines (used for sport fishing) and commercial fishing nets causes significant mortality at sea and on larger. The species is also susceptible to avian botulism so may be threatened by future outbreaks of the disease.

Protected under the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA).

Diet: Predominantly of fish, as well as crustaceans, mollusks, aquatic insects, annelid worms, frogs, other amphibians and plant matter (e.g. Potamogeton spp., Salix spp. shoots, roots, seeds, moss and algae).

They are stealthy divers, submerging without a splash to catch fish. 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.

Nesting: Sexes are alike. They are large, diving water birds with rounded heads and dagger-like bills. They have long bodies and short tails that are usually not visible. In flight, they look stretched out, with a long, flat body and long neck and bill. Their feet stick out beyond the tail unlike ducks and cormorants, looking like wedges.

In summer, adults have a black head and bill, a black-and-white spotted back, and a white breast. From September to March, adults are plain gray on the back and head with a white throat. The bill also fades to gray. Juveniles look similar, but with more pronounced scalloping on the back.

Pairs and groups often call to each other at night. In flight, notice their shallow wing beats and unwavering, bee-lined flight path. Loons are water birds, only going ashore to mate and incubate eggs.

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. Loons also perform a territorial display of lifting their body upright and flapping their wings vigorously.

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 drop-off 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.

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.

1-2 brown eggs with dark splotches are laid. If nesting is successful, loon chicks can be seen going for a ride around the lake on a parent’s back.

Cool Facts: The North American name of "loon" is a reference to the bird's clumsiness on land, and is derived from Scandinavian words for lame, such as Icelandic "lúinn" and Swedish "lam".

Loons are best known for their eerie calls that echo across clear lakes of the northern wilderness, a common sound effect in almost any film taking place in the near a lake. Writer John McPhee described the call as “the laugh of the deeply insane”. The voice and appearance of the great northern loon has made it prominent in several Native American tales. These include a story of a loon which created the world in a Chippewa story; a Micmac saga describes Kwee-moo, the loon who was a special messenger of Glooscap (Glu-skap), the tribal hero; native tribes of British Columbia believed that an excess of calls from this bird predicted rain, and even brought it; and the tale of the loon's necklace was handed down in many versions among Pacific Coast peoples.

Folk names include big loon, black-billed loon, call-up-a-storm, ember-goose, greenhead, guinea duck, imber diver, ring-necked loon, and Walloon.

A hungry loon family can put away a lot of fish; Biologists estimate that loon parents and their 2 chicks can eat about a half-ton of fish over a 15-week period.

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.

The great northern loon, where it is known as the common loon, is the state bird of Minnesota and the provincial bird of Ontario. The loon also appears on the one dollar Canadian coin called a “looonie”.

Found in Songbird Remix Waterfowl Volume 4: Geese Loons, Grebe & Coots

Personal tools