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Birds have been of ecological and economic
importance to humans for thoUKnds of years. Archaeological
sites reveal that prehistoric people used many kinds of birds
for food, ornamentation, and other cultural purposes. The
earliest domesticated bird was probably the domestic fowl
or chicken, derived from jungle fowls of Southeast Asia. Domesticated
chickens existed even before 3000 bc. Other long-domesticated
birds are ducks, geese, turkeys, guinea-fowl, and pigeons.
Today the adults, young, and eggs of both
wild and domesticated birds provide humans with food. People
in many parts of Asia even eat nests that certain swiftlets
in southeastern Asia construct out of saliva. Birds give us
companionship as pets, assume religious significance in many
cultures, and, in the case of hawks and falcons, perform work
for us as hunters. People in maritime cultures have learned
to monitor seabird flocks to find fish, sometimes even using
cormorants to do the fishing.
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Birds are good indicators of the quality
of our environment. In the 19th century, coal miners
brought caged canaries with them into the mines, knowing
that if the birds stopped singing, dangerous mine gases
had escaped into the air and poisoned them. Birds provided
a comparable warning to humans in the early 1960s, when
the numbers of peregrine falcons in the United Kingdom
and raptors in the United States suddenly declined.
This decline proved to be caused by organochlorine pesticides,
such as DDT, which were accumulating in the birds and
causing them to produce eggs with overly fragile shells.
This decline in the bird populations alerted humans
to the possibility that pesticides can harm people as
well.
Today certain species of birds are considered to be
indicators of the environmental health of their habitats.
An example of an indicator bird is the northern spotted
owl, which can only reproduce within old growth forests
in the Pacific Northwest.
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Many people enjoy bird-watching. Equipped
with binoculars and field guides, they identify birds and
their songs, often keeping lists of the various species they
have witnessed. Scientists who study birds are known as ornithologists.
These experts investigate the anatomy, behavior, evolutionary
history, ecology, classification, and species distribution
of both domesticated and wild birds.
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