How fast do peregrine falcons fly?

In level flight, peregrines are fast but no faster than many other birds. Peregrines excel in diving at high speeds, usually in pursuit of prey. The maximum peregrine dive speed has been estimated at approximately 220 miles per hour. Typical dives range between 150 to 200 miles per hour. Although several other species of birds may on rare occasions reach comparable speeds, the peregrine falcon is certainly one of the fastest animals on earth.

What do peregrines eat?

Peregrine falcons are almost exclusively avian predators. They catch and eat other birds, usually on the wing. Pigeons are a favorite source of food, but falcons are very opportunistic hunters and eat a wide variety of prey. On rare occasion, small mammals are also eaten. Peregrine falcons are renowned for their hunting ability, and it is while hunting that they use their spectacular powers of flight to the utmost.

Where do they go in the winter?

The answer is complicated. Naturally occurring populations, or subspecies, show tremendous variability in their migratory behavior. Some subspecies do not migrate at all. Others travel great distances. For example, the tundra subspecies nests on the arctic tundra of North America and winters as far south as central South America. Due in part to its genetic mixture, the reintroduced population demonstrates all of this variability. Some birds, even those with very northern territories, do not migrate. Others do. The proportion of non-migratory birds appears to be increasing, and a form of natural selection may be the reason. Particualrly at sites where competition is high, migratory birds can return only to find that their nest site is now occupied by someone else.

Do the Fargo peregrine’s migrate?

To date, all of the peregrines who have established themselves in Fargo have migrated. They typically leave in September or October and return the following March. With one exception, the Fargo falcons have not been sighted in the winter, so we do not know exactly where they go. On February 23, 2004, our female at the time (Frieda) was photographed in St. Paul, Minnesota. It is not known if she spent the winter in that area or was simply moving through.

How long do they live?

Peregrines have a long life span. Individual birds have been known to live in captivity for more than twenty years. To date, the longest a peregrine is known to have lived in the wild is nineteen years. Of course, typical life spans are shorter and first year mortality rates are high. If a falcon survives its first winter, however, the odds of continued survival improve dramatically.

Do peregrines mate for life?

Not exactly. Like many animals, falcons are extremely territorial. Once they have established a territory they will typically return to it each year, and defend it against intruders. Because this is true of both male and female falcons, the same birds will frequently reunite every spring at their common breeding territory. In this manner, they may continue to mate over an extended period of time. However, pairs do not stay together during the winter. Furthermore, should one member of a territorial pair fail to return or be displaced, the other bird will readily accept a replacement.

When do peregrine falcons begin to breed?

On occasion, falcons begin to breed the year after they hatch. This was particularly true when the reintroduced population was young, and there was limited competition for breeding territories. Most birds do not breed until they are at least two years old, and fully mature. If they are delayed in finding a territory or mate, it may take individual birds even longer. For example, Dakota Ace was three when he first laid claim to Fargo, and four when he first became a father.

How long do peregrines breed?

An extreme example is Meg, who raised a total of 43 young over 16 seasons. She also established a longevity record for wild female peregrines, and was 17 years old when she recently died. In general, territorial males seem to hold a survival advantage over females. This may be that conflicts among female birds are more often fatal. The most productive male to date was Kato, who nested for 14 years on the Colonade Building in Minneapolis, fathering a total of 47 young.

Do they build a nest?

The short answer is no. Most of the manmade structures built for peregrines contain a nest tray filled with gravel. The birds will typically form a depression where the eggs are laid (“scrape”), but no other form of nest building occurs. If natural nest sites are utilized, the eggs are laid directly on the ledge or cave utilized as a nest site. On rare occasions peregrines may use an abandoned nest built by some other raptor as a platform on which to lay their eggs.

How many eggs do they lay?

Clutch sizes vary from one to five. Three or four seems to be the norm. Eggs are laid at intervals of two to three days. Incubation usually does not start in earnest until the clutch is almost complete. The female typically does most of the incubating, and during this period is fed by the male. The incubation period is approximately thirty-three days. The young then spend up to six weeks in the nest until they are old enough to fly, or “fledge.”

What happens to the young peregrines?

After fledging, the young remain dependent on their parents for a period of time, while they improve their flight skills and learn to hunt for themselves. Over time the fledglings become increasingly independent and dispersed. Within one or two months full independence is gained, and the young break all bonds with their parents and nest site. The ultimate dispersal process is random. Individual birds often travel considerable distances in the search for a territory of their own. The birds who have appeared in Fargo in recent years are typical of this dispersal process. The male was released in Sioux Falls, South Dakota, and arrived in Fargo three years later. The three females were hatched respectively in or near Omaha, Nebraska; Alma, Wisconsin; and Becker, Minnesota.

What has happened to Fargo’s fledglings?

See the page entitled “Individual Biographies” for information about the known subsequent histories of all the peregrines who have been raised in Fargo, or their progeny.

Is the bird in my yard a peregrine?

Very unlikely. We only have one pair of nesting peregines in Fargo/Moorhead. There are only two pairs in the entire state of North Dakota. The Fargo nest site is on the Bank of the West building. Peregrines do not nest in trees and almost never venture into backyards. When resting or sleeping, both the adults and young almost always use one of several high structures in the downtown area. They prey almost exclusively on other birds, and do most of their hunting at or above tree top level. Therefore, any hawk-like bird seen sitting or nesting in a tree, hunting in a backyard, or splashing in a birdbath is almost certainly not a peregrine falcon. For example, Cooper’s hawks are now common nesters in this community, and they are usually found in areas with large trees (where they nest). From an appearance standpoint it is easy to mistake these birds for a peregrine, but from a behavioral standpoint they are very different. An easy way to differentiate between peregrines and other raptors is to look for leg bands. Any peregrine seen in this community during the nesting season will almost certainly have conspicuous bands on both legs. Accordingly, any raptor not marked in this manner is not at all likely to be a peregrine. See the page entitled “Banding/Identification” for further information.