What caused the Peregrine Falcon to become Endangered?

The peregrine falcon is endangered by several factors:

1: Pesticides. During th 1950s - 70s, a 'mirical' pesticides was invented, the DDT (Dichloro-Diphenyl-Trichloroethane). But the pesticide has a great effect. It killed the insect efficiently, but the animals consuming the insects stored the DDT in the body. Raptors (not only the peregrine, but a massive range of animals) ate the animals gained massive amount of the pesticide, and the problem appeared. The pesticide interfered with the reproduction of the bird, thinning the eggshells which reduce the number of eggs that survived to hatching. In several parts of the world, such as the eastern USA and Belgium, this species became extinct as a result.

2: Hunting. The Peregrine Falcon have been shot by humans because they eat carrier birds. Carrier birds are used in France to deliver messages and because the Peregrine Falcon have been eating them messages couldn't go through.

3: Black markets. Peregrine eggs and chicks are often targeted by black marketeers and unscrupulous egg collectors. As a result, fewer survivors.

Luckily, the problem has been spotted. Governments have laws to protect the peregrine, and other bird or prey (they met the same or related problems). SPCAs have projects or something to protect the animals. And the peregrine now is globally wide spread, and the LUCN has grossed it out from the endangered list.

Yes. You may not see the peregrine flying in the sky, not even one, but it is normal. In fact the peregrine is a wild bird and is a bird of prey. Both characteristics shares the point of rare to be seen. So be patient, it may soon appear.