Forest Preserve District of Cook County, Illinois
Nature Bulletins
Newton Home Page

Introduction and Instructions

Search Engine

Table of Contents

Copyright

Disclaimer

Eagles and Buzzards
Nature Bulletin No. 245-A   November 19, 1966
Forest Preserve District of Cook County
Seymour Simon, President
Roland F. Eisenbeis, Supt. of Conservation

EAGLES AND BUZZARDS
Until the Bald Eagle was adopted as our national emblem of freedom by the Second Continental Congress in 1782, an eagle had been the emblem of conquerors. It was engraved on tablets and seals of kings who ruled more than 6000 years ago. It was regarded with reverence by the ancient Greeks and later by the Romans who made it the emblem of their republic and, later, of the Roman empire. As a silver bird on a tall standard it was carried at the head of every legion in their armies.

All birds of prey have the most highly developed organs of vision in the world. In most kinds the eyes are so large that the two eyeballs occupy more space in the skull than does the brain, and are equipped with many special muscles so that the eye can be instantly transformed from a telescope to a microscope. There is a record of a bald eagle, soaring at great height over a big lake, diving diagonally downward to pick up a floating fish three miles away.

Of about 80 species of eagles known in the world, we have three in North America: the Southern Bald Eagle, the slightly larger Golden Eagle, and the Northern Bald Eagle which breeds in northern Canada from Alaska to Labrador. The latter, with the exception of the California Condor which is nearly extinct and has a wingspread of from 9 to 11 feet, is our largest bird of prey. A peculiarity of these eagles is that the females average somewhat larger than the males.

A few southern bald eagles are seen near Chicago every year, usually during the fall or winter. In October, 1949, five were seen soaring over our Palos preserves, wheeling in great overlapping circles high in the sky. This eagle feeds principally on fish, both alive and dead, and frequents the shores of lakes and large rivers. They formerly nested among the Indiana dunes and in the great Kankakee Marsh. The nest is built high up in a big tree, never very far from water, and is a huge bulky mass of large sticks with a shallow bowl of finer material. Eagles are presumed to mate for life and occupy the same nest year after year, adding to it each spring, when the female lays two, rarely three, ivory white eggs.

The head, neck and tail of the adult is pure white, the body being sooty brown and the wing nearly black. Immature bald eagles, however, until they are three years old and become adult, are dark-feathered throughout and greatly resemble the Golden Eagle, a bird of the wild mountainous countries which has been seen soaring over the Chicago region on rare occasions in recent years.

Another big bird seen here almost every year and sometimes mistaken for an eagle, is the Turkey Vulture or Turkey Buzzard. The buzzard, however, has a shorter neck, a much smaller head -- naked and covered with red wrinkled skin -- and soars with its wings tilted slightly upward in a broad wide V; whereas the eagle's wings are outstretched in almost a straight line. In fair weather the buzzard, a big ugly blackish bird with a wingspread of nearly 6 feet, can soar for hours, slowly circling on motionless wings. Sometimes one rides an updraft in ever-widening spirals until it is a mere speck in the sky. From such heights, with its marvelous vision, it can detect a dead animal as small as a rabbit and swiftly descends to feast upon the rotting carcass which it tears apart with its powerful hooked beak. They make no nest but lay two, rarely three, eggs in a hollow log, a brushpile, an old stump, among rocks or in a cave. The filth they eat is disgorged to feed their young, which are even more ugly and revolting than their parents.

On pay day the eagle screams.


To return to the Nature Bulletins Click Here!
Hosted by NEWTON

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Sponsered by Argonne National Labs