Saturday, 2 February 2013

Common Loon

order : Gaviiformes      Genus & Species : Gaviidae     Family : Gavia immer

Sleek and exquisitely marked, the common loon haunts secluded lakes, announcing its presence with an eerie cry that travels far across its remote home. The common loon’s streamlined body is enhanced by legs set far back, providing great maneuverability and power on and under water. They breeds across northern North America, Iceland and Greenland; winters as far south as Florida and California; also occurs in western and northern Europe, occasionally nested in Scotland. 

Habitat : An aquatic bird, the common loon spends almost all its life on water. This is because of barely walk on land due to the extreme rear placing of its legs on its body. In the breeding season,  it’s found on large, remote ponds and lakes in high latitudes of the Arctic tundra and northern North America. After breeding and before winter sets in, the loon may migrate long distances, flying south to warmer, ice-free waters, especially along coasts. It frequents the seas off rocky headlands and in sheltered bays. Migration across North America also brings it to inland waters; large numbers are in the Great Lakes area in spring and fall. 
Food & Hunting : The loon hunts fish, amphibians and aquatic invertebrates, such as mollusks and crustaceans, normally about 30' below the surface. A typical foray underwater lasts for about one minute, although dives of up to eight minutes have been recorded and depths of over 230' are occasionally reached. The bird’s throat is expandable, letting it accommodate large fish. However, some loons have tried to swallow large flounders and the fish become wedged in their throat, causing the birds to suffocate. 
Behavior : In the spring and early summer breeding season, loons make their presence known and defend their nesting territory with calls. The yodeling calls have a haunting quality that has been described like “maniacal laughter.” For the rest of the year, the birds are silent. Visual displays are also used to communicate.
Breeding : Loons mate for life and are highly territorial, defending the nest against all intruders. Tiny offshore islets are the usual site for nests; these offer protection from predators that steal eggs. Both parents incubate the spotted eggs for about a month.The chicks, usually two, hatch covered with dark down. They leave the nest soon after hatching and are precocious swimmers and divers. But most of a chick’s early life is spent riding around on the back of one of its parents, nestled among the feathers for protection and warmth. Although chicks can dive within a day of hatching, it takes up to six weeks for them to become efficient hunters, so the parents need to fish for them in the meantime.

Bill : Long, sharp, daggerlike bill is adapted to catching fish.The loon strikes its prey with the bill partly open. It also uses its bill to stab at birds that come too close to its nest. 
Wings : Wings are small and pointed. They carry a high wing loading (ratio of a bird’s bodyweight to its wing area), making it necessary for the loon to patter over the surface of the water for some distance before the wings create enough lift to get the bird airborne. 
Legs & Feet : Short, powerful legs are set far back. In this position, the legs are able to move through a long backstroke to gain maximum thrust from the webbed feet.They also extend to act as rudders for steering. 

Weight : 6–10 lbs. 
Length : 27-36"
Wingspan : 4-5'
Sexual Maturity : 2 years
Breeding Season : May–July 

The common loon is called the “loon,” because of the “lunatic” sounds of its wailing cries.

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