Human Activities Harmful to Birds

Since about 1600, more than 100 species of birds are known to have become extinct, virtually all because of such human activities as hunting and land development. In the late 1600's the dodo, a flightless bird found on the island of Mauritius, was killed off by hunters and by animals introduced by colonists. The passenger pigeon, one of the most common birds in North America in the early 1800's, disappeared from the wild by 1900 because of large-scale hunting and destruction of its habitat. Other birds killed off by humans include the great auk, Labrador duck, and heath hen.

Species of birds that have become endangered because of hunting or habitat destruction include the whooping and sandhill cranes, the Andean and California condors, the wood stork, and the resplendent quetzal. Before they were banned in many countries in the 1970's, DDT and certain other pesticides caused the near extinction of the brown pelican, bald eagle, peregrine falcon, and many other species. DDT accumulated in the fat of birds and caused females to lay sterile eggs or eggs with shells so fragile that the eggs could not be incubated.

Are Flightless Birds in Danger?

Some flightless birds are in danger. The ostrich can no longer be found in much of its original habitat. The Galapagos penguin is in danger of becoming extinct, or dying out completely.

Flightless birds are in danger for many reasons. People have turned the feeding grounds of rheas and the ostrich into grazing lands for farms. People also hunt many flightless birds for their feathers, meat, and skin.

Oil spills from ships are a serious danger to penguins. Even a small amount of oil of this kind can hurt a penguin’s feathers and destroy its ability to stay warm in cold seas. Overfishing is also harmful to penguins. When too many fish are taken from the seas, these birds can lose much of the food they depend on.

International laws have been passed to protect many flightless birds. In addition, some of these wild animals are bred on farms.

Yes, some swimming birds are in danger. But over the years, people have made great progress in protecting our wildlife. Today, many swimming birds that were once in danger are increasing in numbers.

During the 1800’s and early 1900’s, many birds were hunted for their meat and feathers. Trumpeter swans were greatly overhunted. It is believed that fewer than 70 swans were left in the United States in 1933.

Since that time, laws have been passed to protect birds and their habitats. One law, passed in 1934, is known as the Duck Stamp Act. Each year, a new stamp is issued that hunters must buy. The money raised is used to buy land and set up wildlife refuges. Today, because of laws like the Duck Stamp Act, there are about 16,000 trumpeter swans.

In the United States and Mexico, the California condor is an endangered species. Here you see a baby condor that is being raised in a zoo. At the right is a condor hand puppet, which is being moved by a zoo worker. The baby thinks it is a real condor—maybe even its mother. The puppet helps the chick get used to being around condors.

In other parts of the world, some hawks, falcons, and kestrels are also endangered. Harpy eagles are rare—and are in danger of becoming extinct. The Spanish imperial eagle is on the list of endangered animals.

Owls, hawks, and other birds of prey need places to nest. They also need wide areas in which to hunt for prey. Unfortunately, many birds of prey are losing their homes. Their natural habitats are being destroyed. Conservationists are working to protect those habitats. They are also setting aside nature preserves, where the birds can live in safety.

The heath hen was a kind of grouse found in parts of the United States. It became extinct, or died out, in the 1930’s, primarily because so much of its habitat was lost that it could not survive. Some other galliforms may be in danger of becoming extinct, too.

The main danger to galliforms is the activities of people. Towns and cities spread into areas that were once wild grasslands and woodlands. These habitats had made good homes for such animals as quail.

Farmers sometimes use chemicals called pesticides (PEHS tuh sydz) to kill harmful insects in their fields. But the chemicals kill all kinds of insects. Quail and other birds are sometimes unable to find enough insects to feed their hungry young.

When large mowers cut an alfalfa field or tall grass on the side of a road, the mowers can chop up the quail nests and eggs hidden in the vegetation. Many young quail are saved when the mowing of fields and roadsides is delayed until the quail nesting season is over, but this practice is not always followed.