These materials consist of various kinds of sticks, especially pine boughs. These scented boughs act as parasite control by repelling insects that find the smell unappealing. The nearest paper birches are now found in Nebraska. The tall prairie grasses of the foothills are also relicts - leftovers from the Ice Age climate. Peregrine Falcons are found throughout North America but are not common anywhere.
Plumage varies distinctly between adults and juveniles.
Adults have dark heads with dark mustache marks that contrast sharply with black streaking on white underparts. Juveniles have darker underparts such that the black streaking is not quite as prominent. Unlike the Golden Eagle, most Peregrines search for ledges on a rock face rather than a nest. They scrape out any debris that has fallen on the ledge during the winter or previous years. The Prairie Falcon looks much like the Peregrine, although its coloration is overall more pale.