Nature Bulletin No. 440-A January 15, 1972
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation
When people settle in a new land they always bring to it plants and
animals that are strangers there. The early colonists in North America
brought the seeds of grains, grasses, clovers, garden crops and flowers
they grew in Europe. They brought horses, cattle, sheep, goats, swine,
poultry, cats and dogs. They brought honeybees because there were
none here. Unfortunately, mixed with their seeds or in forage for their
animals, they brought the seeds of many pesky weeds. As stowaways,
they brought rats, mice and injurious insects.
The colonists found a continent teeming with a great abundance and
variety of wildlife, including billions of wild pigeons, ducks, geese and
turkeys, but they brought their own domesticated kinds, including
turkeys which had been introduced into Europe from Mexico by the
Spaniards. It is a curious fact that our only domestic animal native to
North America is this noble bird.
The Indians had one, the dog, but that was descended from those that
accompanied their ancestors when they came here from Asia in
prehistoric times. When explorers reached the Great Plains they found
Indians riding mustangs, and herds of wild ones, descended from the
horses brought by Spanish conquistadors. In Texas they found herds of
wild longhorn cattle descended from those brought to Mexico in 1521.
Domesticated animals and plants can be controlled because they require
man-made conditions and careful tending. But when a wild species is
introduced into an area where it never lived before, there is no telling
what may happen: either it will multiply and spread like wildfire or it
will soon disappear. If it spreads, it may prey upon some native species,
or crowd it out, or interbreed with them, or infect it with serious new
diseases and parasites. These things happened when people began to
import foreign kinds of wildlife.
The nightingale and the skylark disappeared because the English
sparrow, brought here in the 1850's to control insect pests, spread so
fast that by 1875 it had crossed the continent. Similarly, the starling has
increased enormously and become a pest since 1890 when 60 of them
were released in Central Park, New York. Carp, introduced as a food
fish in the 70's and sold for $80 per pair, have become a nuisance in
streams and lakes all over the country.
Since our Gulf coast swamps were stocked with the Coypu or Nutria, a
large aquatic rodent from South America, the more valuable muskrats
are decreasing. On the other hand, when muskrats were introduced into
California, England and Europe they became serious pests because they
burrowed into earth dams and canal banks. The mongoose, brought to
Hawaii and the West Indies for controlling rats, has played havoc with
ground-nesting birds on those islands. Now, in some states, sportsmen
are insisting that the large European or San Jua rabbit be imported to
improve hunting, in spite of the fact that large parts of Australia were
devastated by enormous numbers of this animal.
It is true that the ringneck pheasant furnishes sport for hunters in
midwestern states where bobwhite quail and prairie chicken have
become scarce. So does the Hungarian partridge in some places.
Therefore, in areas where our native grouse are scarce, sportsmen want
to bring in European grouse. Others suggest European or Asiatic deer
for our western grasslands. Rather than introduce new species of
wildlife, we should spend more thought and money on restoring habitats
for native species.
What is our America to be -- a zoological garden?
To return to the Nature Bulletins Click Here!
Update: June 2012