A common loon in the process of molting into its breeding plumage
April 2, 2017
NATURE
Jim McCormac
A common loon in the water looks like a surfaced submarine. With a quick flick of its feet, the bird slips below the surface; it might reappear a far distance from where it submerged.
The loon is a large diving bird, far more at home in water than on land. A chunky specimen can weigh 10 pounds, stretch nearly 3 feet from bill to tail tip, and have a wingspan of almost 4 feet.
Large, paddlelike feet are located at the bird’s extreme posterior, the better to propel it into the depths. Loons are extreme divers, capable of submerging to 200 feet. Their quarry are small fish and other aquatic prey, which are seized with the large daggerlike bill.
An adult loon in its breeding finery is quite showy. Bright, ruby eyes are embedded in the coal-black feathering of the head and neck. If the sun glints off the bird, a subtle purplish-green gloss reflects back. The black upper parts are stippled with white checkerboarding and artistic bands of creamy slashes create necklaces around the throat.
Loons in nonbreeding condition are far more muted, mostly dingy brown with a whitish throat, breast and underparts. The bird pictured with this column was photographed in mid-March and is molting into its breeding plumage.
The physical appearance of the loon is trumped by its calls. On breeding lakes, and sometimes in migration, loons issue what might be the most spectacular calls of any North American bird. Howard Eaton, writing in 1910, captures the essence: “The scream of the loon, uttered at evening, or on the approach of a storm, has to my ear, an unearthly and mournful tone resembling somewhat the distant howl of a wolf. It is a penetrating note, loud and weird.”
To many, the common loon is a symbol of wilderness: the north country, sparsely populated, clad in vast expanses of boreal forest and dotted with pristine cold-water lakes. Places like northern Michigan and Minnesota and the wilds of Canada.
Charismatic loons are much beloved by people and numerous organizations have been formed to protect them. While much of the population breeds far enough north that human disturbance isn’t an issue, southern populations are threatened. Glacial lakes in populated areas are subject to shoreline development, increased boat traffic and water pollution, none of which favors loons.
While loons nest well to the north of Ohio, large numbers occur here in migration. The past few days have brought numerous reports from lakes all over the state as the loons push north.
Far more loons pass through in late fall, transiting Lake Erie on their way to winter on open waters of the Atlantic Ocean. Peak passage is in November and a prime day might result in a tally of 1,000 birds.
Although loons don’t breed in Ohio, our water management, especially of Lake Erie, is important to their well-being. The big lake is a major migratory thoroughfare and recent algae issues and the likelihood of in-lake giant wind turbines might not bode well for loons and many other waterbirds.
Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com.
No comments:
Post a Comment