Friday, September 7, 2012

Loons by Edward Howe Forbush

There are five species of Loons (Gaviidae Family) in North America, two being common in New England: the Big or Great Northern Diver and the Pacific Loon which has a black-throat but is distinct from the Black-Throated Loon found off the coasts of Europe.

Loons have stout, strong, straight, narrow, tapering sharp-pointed and sharp-edged bills with which they strike and hold their prey which consists primarily of fish but may also include frogs, crayfish, crabs, mollusks, leeches and aquatic insects. They can also subsist on aquatic vegetation; both Audubon and Dr. B.H. Warren noted that they found such food in Loon’s stomachs.

Loons are especially noted for their diving powers, the long distances they travel underwater and their great speed beneath the water where they use both their feet and wings for propulsion. They can alter their specific gravity quickly and swim with the body wholly or partly under the water, with only the head and neck exposed.

Loons are only summer residents of the inland lakes of Northern New England. They spent the winter along the New England Coasts, primarily off-shore. The Loon is a wonderful, powerful living mechanism fashioned for riding the stormy seas. See him as he mounts high above the waves, neck and legs fully extended “fore and aft”, and a bill trifle raised which gives to his whole form a slight upwards bend, his wings beating powerfully and moving as steadily as the walking-beam of a side-wheel steamship. He is driving straight ahead into the teeth of the gale and making greater headway than the laboring steamer that steers a parallel course. Now he slants downward, and striking just beyond the top of a towering wave shoots down its inclined surface and rises again on the coming crest. Here, midway of the wide bay where the seas are running high and wildly tossing their white tops, with a wintry gale whipping the spray from them in smoky gusts, the Loon rests at ease, head to the wind and sea like a ship at anchor. The tossing and the tumult disturb him not, as he rides, light as a birch canoe, turning up his white breast now and then on one side as he reaches unconcernedly backwards to preen his feathers. His neck narrows at the water-line into a beautifully modeled cutwater. His broad paddles push his breast to the tops of the great waves, where it parts the foam as he surmounts the crests and glides easily down the gulfs beyond. The freezing spray that loads the fishing fleet with tons of ice seems never to cling to his tough, glossy plumage; or if it does, he washes it off among the fleeing fishes away down in the warmer currents near the bottom of the bay, as deep as 90 feet.

Often Loons swallow little fish under water but they will bring larger and stronger fish to the surface and mauls them there. If such a fish escapes, the bird dives in pursuit and soon overtakes its prey. It is difficult to see how a Loon manages to swallow a flounder ‘as wide as a man’s hand’, but they do catch and eat such fish. On March 11, 1922, in Nantucket Harbor, I saw a Loon swallow two within half an hour. Both fish seemed dead when brought to the surface as they did not struggle. It would be interesting to know how the bird killed them underwater. The loon worked a long time with the flounder in its bill, apparently crushing it, and finally swallowed it with apparent ease. Crabs are bitten and broken in preparation for eating and their legs are often discarded. There is no very convincing argument that Loons kill and eat other birds though one writer has observed that Loons seem to be very hostile to ducks.

When the ice begins to break up in April and May the migration of Loons from the coasts begins. In breeding season Loons love the solitude of northern lakes where shores are shaded by fir and spruce and pure water seldom mirrors a human face. Islands in quiet lakes are their favorite nesting sites and there in June or July the young are hatched.

Nevertheless, Dr. Coues had an excellent opportunity to watch some Pacific Loons at the Bay of San Pedro on the coast of southern California in 1865 where, as they had been little hunted, he had no difficulty in securing all the specimens that he desired. He says they were tamer than any other waterfowl he had ever seen. They came up to the wharves and played about as unconcernedly as domestic ducks. They swam constantly all about the vessels in the harbor and were evidently not frightened or hurried in the least by any human agency. In New England, however, they were “shot out” at great expenditure of powder and lead and other forms of persecution. They almost died out but there numbers and amiability to human presence have increased in recent years due to protective measures.

{Loon populations are affected by air and water pollution, and face many threats related to the impacts of human activities, including recreational use of their aquatic habitat, fishing with toxic lead sinkers, and shoreline development.

Mercury, a byproduct of coal-burning power plants and trash incineration, is one of the airborne pollutants threatening loons. It is transported to the Adirondacks and other loon habitats through prevailing winds, and falls to the ground in the form of rain or snow. Along with acid rain, the mercury can then enter lakes, where it is converted into a more toxic form called methylmercury, which accumulates in the aquatic food chain. People, loons, and other top predators are most impacted by this concentration of toxins in the food supply. The neurotoxins concentrated in loon prey can affect the birds’ behavior, reproduction, and eventually, their population numbers.

Invasive plants such as Eurasian watermilfoil and curly-leaf pondweed can negatively impact the fish population, lake ecology, recreational use, and ultimately the loon use on a lake.

Removal of woody debris from the water has been documented to cause population crashes in perch populations on a lake. Perch are the primary food for loons so a crash in the perch population may result in less food for chicks and loons abandoning their use of a lake. Fish populations rely on good aquatic plant and woody debris structure for protection and nursery areas. Leaving a buffer zone of native plants along the lakeshore will provide nesting cover for loons and other birds.

Four-stroke motors contribute less pollution to the water and air. They are more efficient and use less oil-based products compared to older two-stroke motors. Hundreds of loons (for some states this is equal to their entire population) can die in one oil spill. Oceanic oil spills can have major ecological impacts as well as catastrophic effects on wintering loons.} *

Although the Loon is graceful and swift on or in the water, it is at a disadvantage on land. For one, it can hardly rise into the air from land nor from the water unless aided by a head wind, and it must have more room than can be furnished by a small pool, and even then it is obliged to flutter and run spatteringly along the surface for some distance to get impetus enough to rise in the air. When the young are well grown, the family, often joined by neighboring adults, frolic for a brief time on the water and then fall into line side by side, and, lifting their wings simultaneously, run an apparent foot race over the surface with ‘incredible speed’ for a quarter of a mile, and turning race back to the starting point. Thy repeat this over and over again. During these races the wings are held out and about half opened. At the end of the performance the male, female and neighbors leave for other fishing grounds and the young scatter to find food. This pay evidently tends to train the muscles of the young birds and to fit them for flight.

Once airborne the ordinary, steady, level flight is familiar to all who know the bird but under favorable conditions it can also soar or circle with set wings.

On our coasts Loons are rarely seen on land unless wounded, but Audubon satisfied himself that on their breeding grounds they spend the night on shore. I once saw at nightfall a pair resting on the beach of an isolated island in British Columbia. Mr. Bent says that “when it is safe to do so they often come ashore to sleep” and that he has several times surprised a single bird well up on a beach. The attempts of such a bird to regain the water were more rapid than graceful, as it often fell on its breast as it scrambled down the beach, humping its back, darting its head and neck about and straining every muscle to make speed, with rather surprising success.

It is quite generally asserted that Loons cannot walk well on land. In fact the name Loon is understood to be derived from the old English word “lumme”, a lummox, an awkward person. Though ungraceful on land by reason of its hidebound legs and the peculiar position of its feet, the Loon can make remarkable speed for short distances when racing towards the water. It uses its wings in place of forelegs, like a pair of crutches, Sometimes the bill is also used ‘like a pick’ to keep the balance. and so flaps and scrambles along.

Loons have amazing voices; very loud and resonant calls. At nightfall or before a storm a A-ooo’-oo or as often written O’-O- ooh; a laughing call hoo, hoo, hoo, hoo, hoo uttered in a peculiar vibrating tremolo or something like o-ha-ha-ha-ho!. W.L. Underwood identifies four calls 1) a short cooing note, 2) a long drawn-out known to guides as the night call, 3) the laughing call, 4) the storm call, a peculiar and weird performance. Robert J. Sim described what he called ‘the silly song’, Oh-a-le cleo-pee-a, cleo- per-wer-wer!, a soft mellow pleasing O lair in a rather disconsolate tone.


Often along the coast towards nightfall I have heard the wild storm-call of the Loon far out to windward against the black pall of an approaching tempest like the howl of a lone wolf coming down the wind; and I have seen his white breast rise on a wave against a black sky to vanish again like the arm of a swimmer lost in the stormy sea. Sailors, hearing the call, say that the Loons are trying to blow up an “easterly.” At times his cries seem wailing and sad as if he were bemoaning his exile from his forest lake. Such is the Loon in his winter home off our coast; for there he lives and braves the inclemency of the season. Of all the wild creatures that persist in New England, the Loon seems best to typify the stark wildness of primeval nature.

Birds of Massachusetts and Other New England States by Edward Howe Forbush; The Commonwealth of Massachusetts, Norwood Press, 1925


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