As a predator at the end of its food chain, this was always a rare bird.
With the advent of the persistent insecticides it was almost wiped out, accumulating DDT in its tissues from every infected prey consumed until its egg shells thinned and produced no viable young.
With the banning of DDT and introductions from less contaminated areas it appears to be making some comeback.
This is a crow-sized falcon with dark brown or blue black and prominent “mustache” markings on its face.
When perched, Broad-winged Hawks can look very similar but they lack the toothed beak of a falcon.
In flight the pointed wings and great speed of the peregrine is evident as is its effect on gulls, ducks and pigeons that fly up and scatter in alarm when the Peregrine is just a speck on the horizon.
Dr. J. Murray Speirs