Nature Bulletin No. 574 October 3, 1975
Forest Preserve District of Cook County
Daniel Ryan, President
Roberts Mann, Conservation Editor
David H. Thompson, Senior Naturalist
Every year, in late autumn, we see a few loons on Maple Lake in the
Palos preserves. They stop to rest and feed on their way to the gulf
coast. In summer, fishermen on lonely lakes in the trackless forests of
Canada often hear the weird unearthly cry of a loon. It must have
solitude and, even in a remote wilderness, only a large lake may harbor
more than one nesting pair.
Loons are seldom found on land. They are closely related to the diving
birds of Arctic seas -- the queer looking auks, puffins, murres and
guillemots -- and are cousins to our freshwater divers, the grebes. In
each species, the males and females look alike.
This group is the most primitive of all birds and most closely akin to the
reptiles. The legs are located so far back on the body, with the
"drumstick" buried beneath the skin and feathers of its rump, that the
heel joint is close to the tail. Consequently, on land they squat or stand
in a vertical position, like a penguin, and walk with great difficulty,
using both wings and feet to flounder along.
The Common Loon is a large dark bird with a boat-shaped body that
rides very low in the water, a snaky head on its long thick neck, and a
long narrow sharp-pointed and sharp-edged bill for catching fish. It has
the peculiar ability to sink gradually until it disappears without leaving
a ripple. Presently, some distance away, it emerges just as mysteriously.
The most unforgettable memories of a loon, seen and heard in a
northern wilderness, are of its eerie calls that, at night, shatter the
silence with voices like the wild laughter of a demon or the tortured
howl of a lost soul.
In full breeding plumage the common loon has a purplish-black head
and neck with a patch of narrow white stripes on the throat and similar
patches on both sides of the neck. The upper parts, glossy black, are
thickly marked with large square white spots in rows that give it a
barred appearance. This is a handsome bird -- as sharp as a head waiter
-- with red eyes. However, the adults in winter, and the young until their
second year, are grayish-brown on top.
The loon's nest is a flat two-foot mass of vegetation close to the water's
edge, or anchored to a bed of reeds, or occasionally on a muskrat house.
She lays two dark brown or greenish eggs. When hatched, the precocial
young are covered with down and soon able to swim and dive as well as
Loons feed largely on fish but they also consume quantities of crayfish,
mussels, clams, frogs and aquatic insects. They catch fish in long
underwater dives, sometimes using both wings and the webbed feet for
greater speed. There are numerous records of loons being trapped and
drowned in fishing nets placed 180 to 200 feet below the surface.
Six species of loons nest below or above the Arctic Circle in Greenland,
Canada, Alaska, Siberia, Finland and Scandinavia. Our common loon
winters farthest south but. the Red-throated Loon, smaller, is sometimes
seen here on Lake Michigan.
There are several species of grebes, all resembling loons in many
respects, but only the little Pied-billed Grebe frequents the Chicago
region. Many of them raise their broods on the sloughs and ponds m our
forest preserves. This grebe differs from other species in having a bill
that -- instead of being long and pointed--is thick, blunt, curved
downward at the tip, and circled by a black band. Among its many
common names are Hell-diver, Water Witch and Dabchick. This is the
familiar little ducklike bird that disappears in the water when alarmed
and reappears far from where you last saw it. Nothing can dive as slick
as a dabchick.
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Update: June 2012