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

Introduction and Instructions

Search Engine

Table of Contents

Copyright

Disclaimer

Migration of Birds
Nature Bulletin No. 146   March 13, 1948
Forest Preserve District of Cook County
William N, Erickson, President
Roberts Mann, Supt. of Conservation

MIGRATION OF BIRDS
High in the sky, wild geese are honking as they return to their nesting ground in the far north. Presently, our summer songbirds will appear and the ponds and marshes be repopulated by ducks and shore birds. Some birds, like the juncos and tree sparrows, resident here all winter, will leave for Canada or our northern states, in May, great flocks of warblers will arrive, tarry briefly, and pass on, not to be seen again until they migrate southward in autumn.

The spectacular annual journeys of many kinds of birds, and their homing "instincts", have been a source of wonder since ancient times. In recent years, large-scale marking with small aluminum identification bands upon their legs, has yielded much information about birds their migration routes, speed of travel, summer and winter homes, length of life and life histories.

Many of our summer residents, including the robing and wrens, spend the winter in southern states. Others travel to Central and South America. The bob-o-link winters in Argentina. Some warblers nest in northern Canada or Alaska and winter in Brazil, traveling 5,000 miles to do so. Our tiny ruby-throated hummingbirds fly across the Gulf of Mexico to Central America. The golden plover, in fall migration flies non-stop nearly 2500 miles across the ocean from Nova Scotia to South America. But the champion long distance flyer is the Arctic tern, which travels from Labrador where it nests, across the Atlantic Ocean to Europe and then down to the Antarctic, at the southern tip of South America. Each year it makes a round-trip of 22,000 miles.

The shortening of the daylight hours, cooler weather, and the decrease in their food supply, probably have much to do with the fall migration of many birds. in spring, some scientists believe, the increasing hours of more intense sunlight stimulate a gland which causes the bird to become restless and start northward. But why it winters in one particular place and summers in another, year after year, and how it finds its way between them, traveling usually at night, is still a mystery.


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