Also check here for a live images of Toronto's nesting peregrines. A clutch of up to 4 eggs are laid in the nests which are incubated mainly by the female although the male will take nest-sitting duty occasionally. In about a month, the young chicks hatch which are light colored. They will fledge a little more than a month later. There are few natural predators for adult peregrine falcons.
Young birds become tasty feasts for some mountain cats, martens and large owls.
Like many birds, man is the peregrine falcon's greatest danger. Eating smaller birds that ingested food sprayed with DDT, the peregrines accumulated this poison in their bodies, causing eggs with shells too thin to survive during incubation. By the mid 1960's, there were no peregrines in the eastern United States. The decline spread westwards so that by the middle of the 1970's, western populations had declined by up to 90 percent. The United States Congress banned the use of DDT in 1972 but is still used today in some Latin American countries where some migrating peregrine falcons winter.