- Pesticide use: The widespread use of pesticides, particularly DDT, in the mid-20th century caused eggshell thinning in peregrine falcons and other raptors, leading to a decline in reproductive success.
- Habitat loss: Peregrine falcons rely on cliffs and other natural structures for nesting and hunting, but habitat destruction and development have reduced the availability of suitable nesting sites.
- Hunting and trapping: Peregrine falcons were hunted for sport and their feathers were used in fashion, contributing to their decline.
Conservation efforts, including restrictions on pesticide use, habitat protection, and captive breeding programs, have helped peregrine falcon populations recover in many parts of the world. However, some populations still face threats from habitat loss, pollution, and other factors, and peregrine falcons remain a species of conservation concern in some areas.