Peregrine Falcon (Falco Peregrinus) Bird Information & Facts
Often a falcon can be seen circling a church spire, snatching suddenly at one of the hundreds of wild pigeons that are the scourge of modern-day cities. It is because of them that the peregrine falcon, a handsome raptor, is distributed throughout the whole of Europe, for pigeons are the mainstay of its diet, even during the nesting period.
The peregrine Falcon also hunts other birds. When capturing prey on the wing it climbs above the intended victim, then plummets downward at a speed of up to 280 kilometers an hour, suddenly slowing its flight to attack, striking upward to sink its long talons into the victim’s flesh. On occasion, the peregrine will also catch a small mammal.
Length: 43 cm.
Wingspan: Male — 86 to 106 cm, female —104 to 114 cm.
Voice: A clear and loud, repeated sound resembling ‘kek-kek-kek’ and a short ‘kiack’.
Size of Egg: 46.0—58.9 X 36.3—44.9 mm.
Peregrine Falcon Bird Habitat
Its nest is built in open country in rocky woodland spots which command a wide view, as well as on coastal cliffs and sometimes on tall city towers. The peregrine falcon often avails itself of an abandoned raptor’s nest, especially in wooded regions.
The thinly-lined structure holds 3 to 4 eggs, which are incubated by the hen, relieved now and then by the male. The nestlings, which emerge after 29 days, are covered with a thick downy coat. For the first few days the male forages for food, which he passes to the hen, who divides it before giving it to the young. The male does not know how to do this and gives food directly to the young only when they are old enough to tear it themselves, usually in the third week after birth. After 35 to 40 days the nestlings leave the nest, but remain within close range for some time.
The Wolrd’s Fastest Moving Bird
In level flight the peregrine falcon is not the fastest of all birds so it resorts to a very steep dive known as a ‘stoop’ in order to develop the extra speed required to overhaul and sometimes instantly strike dead prey in the air, (Suzanne Alexander)
Discussion about a bird’s speed
It was a discussion about the speed of gamebirds which gave rise to the idea for the Guinness Book of Records and this has long been a subject at which men have marveled. But because admiration of natural ability has always led to exaggeration and bird speed has been extremely difficult to monitor, a great deal of uncertainty remains.
Bird flight speed is mostly very erratic and many species are capable of level, short-lived bursts at enhanced speed while others can ‘stoop’ or plunge-dive after prey at speeds which greatly exceed those of any species in level flight.
The flight is chiefly a very successful method of locomotion which has enabled birds to exploit changing food sources most rapidly, though it is also useful in display and finding a mate and place to breed. But an individual species’ flight performance speed and energy expended — must be governed by the potential energy value of the chosen food. Powered or flapping flight demands much energy and is minimized by every bird so that the net energy gain is maximized.
Speed comparison of different birds
The optimum flight speed of a species is largely determined by the main food sources. This in turn has partly determined body shape. The two main features traditionally associated with very rapid flight are long, narrow wings, swept back to reduce turbulence and a torpedo-shaped body. These appear to reach perfection in the swifts, but contrary to popular opinion, swifts are among the slowest of birds so far reliably measured in level flight. In fact, this is consistent with the expected performance of long, narrow wings, whose prime function is to permit sustained, energy-saving flight rather than facilitate great speed.
In roosting on the wing and being an aerial insectivore, the swift is not particularly concerned with speed. Level-flight speeds of the common swift (Apus apus) in foraging are around 6.5 m/s or 23 km/h (14 mph). In migration it flies at about 11 m/s or 40 km/h (25 mph).
Thus, even allowing for error through mixing up air and ground speeds, claims that the white-throated spine tailed swift (Hirundapus caudacutus) can feed at 113 km/h (70 mph) and may reach air speeds of up to 170 km/h (105 mph) in courtship display are now doubted. Similar claims for other swifts, such as the alpine (Apus melba), have also been called into question. In feeding, great speed would be a hindrance, but much higher speeds are no doubt reached in display. It is the larger birds with streamlined bodies plus powerful flight muscles which fly the fastest in steady flight.
Eider Duck (Somateria mollissima)
The fastest reliably clocked so far is the eider duck (Somateria mollissima) at 21 m/s or 76 km/h (47.2 mph). This bird also has the highest recorded wing-loading — the smallest wing area relative to body weight. The swifts’ low wing-loading is an adaptation for soaring — gliding at low air speed with a low rate of sink. The powerful flight is an obvious asset for the eider duck, which is a coastal bird spending much of its time battling against strong headwinds. Flight speed rises with both mass and wing-loading since higher speeds become necessary if lift is to be sufficient to support the weight.
Although it is able to catch very fast-flying birds such as pigeons and shorebirds, in level flight under its own muscle-power it can seldom catch up with a good homing pigeon. A maximum level flight speed of 110 km/h (65—68 mph) in short bursts is suggested.
The maximum flight speed of racing pigeons is no more easy to determine than that of wild birds. The woodpigeon (Columba palumbus) has been reliably clocked at 61 km/h (38 mph) in steady, level flight but trained and specially bred racing pigeons can do better. The highest race speed recorded averaged 117.14 km/h (110.07 mph) in the East Anglian Federation race from East Croydon on 8 May 1965 when 1,428 birds were backed by a powerful south/south-west wind. But in level flight in calm conditions, it is doubtful if even a champion racing pigeon can exceed 96 km/h (60 mph). Most birds fly much more slowly without the assistance of the wind.
Peregrine Falcon (Speed up to 180 km/h (112 mph) in a dive)
The fastest-moving bird of all is probably the peregrine falcon (Falco peregrinus) when stooping after prey, but no very accurate determination of speed has been made and the maximum is probably no more than about 50 m/s or 180 km/h (112 mph). Air speedometers have been fitted to trained peregrines and these recorded a maximum speed of 132 km/h (82 mph). The male, or tiercel, is the better flyer and may reach far greater speeds in a display dive, but the accuracy of dives measured to 360 km/h (224 mph) at steep angles has been questioned.
There are many variables to be considered, including the speed of the bird before entering the dive and the speed of any head-, tail-, or cross-wind. The mathematical theory has suggested an even higher dive speed is possible, but even at the lower figures it is baffling how the peregrine can pull out of such a dive and avoid blacking out.
Cosmopolitan in distribution, with 17 races, the 36—48 cm (14—19 in) peregrine has long been the falconer’s choice par excellence. Sadly, this has led to many birds being taken illegally from the wild and sold — mostly to Arab enthusiasts for very large sums of money. In the 1950s and 60s its population was much reduced throughout most of its range by DDT and other organochlorine pesticides, which resulted in direct poisoning through the food chain, loss of fertility and unsuccessful breeding attempts through eggshell thinning and breakage. Many of these chemicals are now banned and the position is much improved in many western countries.
Other Interesting Facts About Peregrine Falcon
The peregrine falcon’s victim is sometimes hit with a glancing blow from the claws, striking it dead in mid-air, but predator and prey may also ‘bind’ together and both tumble to the ground. A strike lasts only one-tenth of a second or less and the feet are lowered and thrown forward at the last moment to increase greatly the impact. Simultaneously the tail may be fanned and the wings thrown up to maximize braking.
The bird is such a skillful flyer that its path may be altered even just a few milliseconds before impact. Usually, there is a characteristic trail of scattered feathers leading to the remains of the prey with the breast-bone picked clean of meat. Despite the great speed, many stoops fail and the hunt often continues as a direct chase. Sometimes, in a desperate attempt to save itself, the hunted bird may fold its wings and allow itself to fall to the ground as the falcon usually gives up if it cannot hunt the prey in flight.
Male peregrines average 700—850 g (241/2—30 oz) and females g (381/2-53 oz). Prey varies considerably according to location and ranges in size from 10 g (0.35 oz) passerines to geese and herons weighing over 2,000 g (4 lb), the heavier female peregrines generally taking the larger prey.
Over 132 bird species have been recorded in the diet of British peregrines and over 200 seems likely for North American birds, Mammals, reptiles, amphibians and even fish are also sometimes taken.
Really severe peregrine strikes can dismember a wing or sever the head of the prey but a mere stun is more likely. The peregrine’s normal cruising speed is probably in the region of 65 km/h (40 mph).