The peregrine falcon is a crow sized raptor. Mature peregrines are characterized by a blackish "moustache" and blueish gray or slate colored upper parts. The under parts are white to buff with brown bars on the sides, thighs, and often the front. The undersides of the wing are white with black bars. Fledgling and juvenile peregrine falcons have brownish upper parts, a dark brown tail with buff colored bars and white tips, and buff colored underparts with blackish brown streaks. Mature plumage is generally obtained during the bird's second summer. Females are usually larger than males. In all plumages, females also tend to have darker and more pronounced coloration on their underparts.

The accompanying photograph is of Dakota Ace, the male peregrine who first claimed Fargo as his territory in 2000 and has been part of every nesting to date.

Peregrines are avian predators, and feed almost exclusively on other birds. Most their prey is caught on the wing. Peregrine falcons diving at prey have been clocked at speeds in excess of 200 mph, making them among the fastest animal on earth. They are superlative flyers, capable of remarkable agility as well as speed.

The peregrine falcon is the most widely distributed bird of prey in the world, with races nesting on every continent except Antarctica. Three races of peregrine falcons occur naturally in North America. Tundra peregrines nest in Greenland and across the arctic and sub-arctic regions of Canada and Alaska. In the winter, members of this highly migratory race travel south to the Carribean, Mexico, Central and South America. Some birds winter as far south as Argentina and Chile. Tundra peregrines are occasionally seen in Fargo during their seasonal migrations.

Peale's peregrines are non-migratory inhabitants of the wet Pacific coast of British Columbia and southeastern Alaska. This is one of the largest and most darkly plumed races of peregrine falcon.

The anatum race or subspecies once nested across much of the mid portion of the North American continent. In North Dakota the anatum peregrine historically nested in small numbers in the Badlands. There are indications that they may have also nested in the Turtle Mountains. Finally, there is a credible report that a pair of these birds nested on the state capitol building in 1947 and 1948.

Following World War II, populations of peregrine falcons, and many other raptors, were decimated by various human activities, particularly the wide spread use of the pesticide DDT. This persistent chemical, and its byproducts, accumulated in the falcons' body tissue, causing females to produce sterile or thin-shelled eggs.

The eggs broke easily during incubation, and few chicks hatched. The anatum race was particularly hard hit. The last known meeting in North Dakota occurred in 1954. By 1970, the peregrine falcon had been essentially eliminated as a breeding species south of the Canadian border and east of the Rocky Mountains.

Due to restrictions on the use of DDT, and to intensive captive breeding and re-introduction programs across the United States and Canada, the peregrine falcon has made a remarkable comeback. Peregrines have been returned to much of their natural range, and have reclaimed many historic breeding sites. They have also become established in many urban environments such as downtown Fargo.

Peregrine falcons are relatively long lived. They have been know to live for more than fifteen years in the wild, and even longer in captivity. Typically they do not begin to breed until their second summer. Breeding pairs are highly territorial, and will usually return to the same nest site year after year. If one of the birds is lost or fails to return, the survivor will often attract a new mate. As a result, nest sites can remain occupied for extended periods of time.

The usual clutch size is three or four eggs. At this latitude egg laying typically occurs in April, and the incubation period is approximately thirty-three days. Fledglings usually leave the nest between forty and forty-five days following hatching, but they continue to be dependent on their parents for food. Over the next several weeks the young birds become increasingly self reliant and independent. Ultimately, they wander off in search of territories of their own. This natural tendency to prospect for an available nest site is one reason the peregrine falcon is now re-established across much of its former range, often in locations where they did not naturally occur. Fargo is fortunate to be one example of this.

Based on the success of the recovery efforts, the peregrine falcon was recently removed from the federal endangered species list. It is still strictly protected, however, by a variety of state and federal laws, as well as international treaties.