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Grebes
Nature Bulletin No. 636-A April 9, 1977
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation
GREBES
Often, on a hushed spring morning with wisps of fog hanging low over
a marsh, the silence is broken by a weird voice floating across the water
-- "Wup-Pup-Pup-Pup-pup-pup-pup-caow-caow-caow-caow. " The call
is somewhat like that of a cuckoo, only louder. Sometimes, heard close
at hand among shoreline rushes and cattails, the secretive owner of the
voice is almost impossible to locate -- now here, now there, the name,
Water Witch, is fitting. Also called the Pied-billed Grebe, Hell Diver,
or Dabchick, it is a small grayish brown water bird that nests each year
in our local sloughs and ponds.
The grebe is a swimmer and a diver. With its long snaky neck held erect
it rides the surface as lightly as a drifting leaf. In this position it can
squeeze out the air trapped under its feathers and slowly sink out of
sight, then pop up a hundred feet away -- perhaps to roll on its back and
preen its silky breast feathers. If frightened, it plunges down with a flip.
They are said to dive at the muzzle flash of a shotgun and be safely
under water before the charge of shot hits. Then with just the tip of the
bill and eyes above the surface they skulk far away until the danger is
past.
They can out-swim and catch fish. The feet are not webbed but are
adapted for swimming by flaps on the sides of the toes. The wings are
small and, on takeoff the grebe splashes along the surface for a long
distance. Migrating on a rainy night, they often come to grief by
alighting on a wet pavement which they mistake for a body of water. On
land they are almost helpless and entirely unable to take wing. With
legs set at the rear of the body and with no noticeable tail, they seem to
have been left unfinished .
Following an elaborate courtship with much splashing and soft cooing,
a pair of grebes builds a bulky floating nest anchored among tall water
plants. The parents take turns incubating the 4 to 8 buffy white eggs
which are soon stained brown from the blanket of wet rotting vegetation
they drag over the eggs each time they leave the nest. The black-and-
white striped young take to the water immediately upon hatching. The
parents often carry the young on their backs and, sometimes, when
alarmed, dive with the grebelets clamped under their wings.
Besides our common pied-billed grebe, which ranges throughout most
of North and South America, the Chicago region is regularly visited
each spring and autumn by the Horned Grebe. Three other species are
seen here on rare occasions -- the Red-necked Grebe, the Eared Grebe
and the Western Grebe or Swan Grebe. This last, the largest of the lot,
has become rather widely known through movies of its spectacular
courtship dance -- a water ballet. With feet rapidly churning, it raises
itself into an erect position with almost the entire body clear of the
water and patters along the surface for several yards.
The grebes' diet is small fish, frogs, tadpoles, crustaceans, leeches,
insects and some plant material. Most of this food is taken by diving but
some is picked from the surface and along shores with their hen-like
beaks. Curiously, grebes of all ages have a ball of their own feathers in
the stomach. It has been supposed that these act as strainers to keep
sharp fish bones out of the intestines.
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