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

****:LOONS

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 
their parents.

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.