Sunday, January 27, 2008

Common Loon - Gavia immer


The Common Loon or "Great Northern Diver" is the Minnesota State Bird. It is easily recognized by its distinctive coloring, white stripes and flecks on black plumage as well as its long, black bill. It is larger than a duck, but smaller than a goose, averaging around 10 lbs in weight.

Minnesota has so many loons because it has so many lakes. Loons, built to dive, are more at home on water than on land. Unlike most birds, they have solid bones, not hollow bones. This extra weight allows them to dive deeply into lakes, up to 250 feet, but also makes it harder for them to fly. Its commonly know that loons only inhabit larger lakes because they require so much take off space to achieve flight. The loon has to run up to 500 feet across the water, madly flapping it wings, until it can finally take off.

Another distinctive feature of the loon is its red eyes. This coloring helps them see better while underwater. The catch most of their prey (suckers, perch, panfish and other small fish), while diving. They can stay underwater hunting up to 5 minutes at time.

Loons have four sounds they make, a tremolo, a hoot, a yodel and a wail. The wail is the soon most commonly associated with loons. It is a long, hollow mournful sound that lasts several seconds.

Because their primary home is on the water, loons have few natural enemies. Young loons might be attacked by large fish, eagles or hawks; but once a loon achieves adulthood, it is relative safe from predators. Loons live to be up to 30 years old.

Humans are the biggest risk to loons. Speedboats have been known to accidentally run down loon parents and young. Mercury and lead poisoning is also a serious problem, and the Minnesota DNR monitors loon populations for these substances.

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