All raptors, except owls, have a crop that stores excess food. The indigestible parts of the prey are formed into a pellet in the gizzard and regurgitated out the mouth. Most raptor pellets contain only the hair, feathers, or exoskeletons of their prey, but owls cannot digest most of the bones, so their pellets also contain bones.
There are several categories of raptor that could possibly be used in falconry. They are also classed by falconers as:-
Broadwings: eagles, buzzards, Harris hawk. (Accipitridae)
* Osprey (Pandion)
The Osprey is a medium-large raptor with a worldwide distribution that specialises in eating fish. Seen in flight from below the osprey has white or slightly mottled underparts. The long wings are angled, bending at the 'wrist' which has a black patch contrasting with the white wing linings, and at a distance it could be mistaken for a large gull. Of the Scottish birds of prey, only the golden eagle and sea eagle have larger wingspans. The osprey can raise itself and a fish weighing as much as 2kg out of the water and can also lift large branches to its tree-top nest.
Its main UK stronghold is in Scotland - nest sites with public viewing facilities are at Loch Garten, Speyside, and Loch of the Lowes, Perth. It recently began breeding in England at Bassenthwaite, Cumbria, where there is a public viewpoint, at Rutland Water (where it was introduced), and a pair can also be found in Wales in the Glaslyn valley where there is a public viewpoint. Can be seen at almost any large body of freshwater during spring and autumn migration. Wingspan: Males 1.5 m, females 1.6m (5 ft)
* Sea Eagles (Haliatus)
Most species of this genus catch and eat fish, some almost exclusively. However, in countries where they are not protected, some have been effectively used in hunting for ground quarry.
* True Eagles (Aquila)
This genus has a nearly worldwide distribution. Most are primarily ground-oriented but will occasionally take birds. Eagles are not used as widely in falconry as other birds of prey, due to the lack of versatility in the larger species (they primarily hunt over large, open ground), the greater potential danger to other people if hunted in a widely populated area, and the difficulty of training and managing an eagle.
* Buzzards (Buteo buteo)
This genus, sometimes known as hawks and not to be confused with vultures, has worldwide distribution. The Red-tailed Hawk, Ferruginous Hawk, and rarely, the Red-shouldered Hawk are all examples of species from this genus. The Red-tailed Hawk is hardy and versatile, taking rabbits, hares, and squirrels; given the right conditions it can catch geese, ducks, and pheasants.
The Common Buzzard is the commonest UK bird of prey, it is quite large with broad, rounded wings, and a short neck and tail. When gliding and soaring it will often hold its wings in a shallow 'V'. It is variable in colour from all dark brown to birds with pale heads and breasts, all have dark wingtips and an unbanded tail. Greatest numbers in Scotland, Wales, the Lake District and SW England. Found on farmland with wooded hills, moorland and in more arable areas to the east where it is spreading. Look for birds soaring over wooded hillsides in fine weather, or perched on fence posts and pylons.
The Red Kite is a very graceful bird of prey and is unmistakable with its reddish-brown body, angled wings and deeply forked tail. It was saved from national extinction by one of the world's longest running protection programmes, and has now been successfully re-introduced to England and Scotland. It was at one time confined to Wales, a reintroduction scheme has brought them back to many parts of England and Scotland. Central Wales, central England - especially the Chilterns, central Scotland - at Argaty, and along the Galloway Kite Trail are the best areas to find them
* The Harris's Hawk (Parabuteo)
Parabuteo unicintus is the sole representative of the this genus worldwide. Arguably the best rabbit or hare raptor available anywhere, the Harris' Hawk is also adept at catching birds. Often captive-bred, the Harris's Hawk is remarkably popular in the UK because of its temperament and ability. They are gregarious birds, one of the few semi-social raptors. Harris's can hunt in groups, a behavior that is a trademark in the wild. This genus is native to the Americas from southern Texas and Arizona to northern South America.
* The True Hawks (Accipiter)
This genus is also found worldwide. The hawk expert Mike McDermott once said, "The attack of the accipiters is extremely swift, rapid and violent in every way." They are well known in falconry use both in Europe and North America.
The Hen Harrier is one of the UK's birds of prey, this is the most intensively persecuted. Once predating free-range fowl, earning its present name, its effect on the
number of grouse available to shoot is the cause of modern conflict and threatens its survival in some parts of the UK. While males are a pale grey colour, females and immatures are brown with a white rump and a long, barred tail which give them the name 'ringtail'. They fly with wings held in a shallow 'V', gliding low in search of food. The hen harrier lives in open areas with low vegetation. In the breeding season UK birds are to be found on the upland heather moorlands of
Wales, Northern England, N Ireland and Scotland (as well as the Isle of Man). In winter they move to lowland farmland, heathland, coastal marshes, fenland and river valleys. Those found in eastern and south-east England are probably mostly visitors from mainland Europe.
* The Falcons (Falconidae)
The Peregrine Falcon is a large and powerful falcon. It has long, broad, pointed wings and a relatively short tail. It is blue-grey above, with a blackish top of the head and an obvious black 'moustache' that contrasts with its white face. Its breast is finely spotted. It is swift and agile in flight, chasing prey. The strongholds of the breeding birds in the UK are the uplands of the north and west and rocky seacoasts. Peregrines have suffered persecution from gamekeepers and landowners, and been a target for egg collectors, but better legal protection and control of pesticides (which indirectly poisoned birds) have helped the population to recover considerably from a low in the 1960s. Some birds, particularly females and juveniles, move away from the uplands in autumn.
Wingspan: 3 feet (90-112 cm)
The Kestrel (sometimes known as the motorway falcon) is a familiar sight with its pointed wings and long tail, hovering beside a roadside verge. Kestrels have been recently declining as a result of habitat degradation due to continuing
intensive management of farmland and so it is included on the Amber List. They have adapted readily to man-made environments and can survive right in the centre of cities. Kestrels are found in a wide variety of habitats, from moor and heath, to farmland and urban areas. The only places they do not favour are dense forests, vast treeless wetlands and mountains. They are a familiar sight, hovering beside a motorway, or other main road. They can often be seen perched on a high tree
branch, or on a telephone post or wire, on the look out for prey.
Wingspan: 2-2.5 feet (68-78 cm)
The Lanner Falcon (Falco biarmicus) is a large bird of prey that breeds in Africa, southeast Europe and just into Asia. It is mainly resident, but some birds disperse more widely after the breeding season.
It is a large falcon, at 43-50cm length with a wingspan of 95-105cm. European Lanner Falcons (Falco biarmicus feldeggi, also called Feldegg's Falcon) have slate grey or brown-grey upperparts; most African subspecies are a paler blue grey above. The breast is streaked in northern birds, resembling greyish Saker Falcons, but the Lanner has a reddish back to the head. Sexes are similar, but the browner young birds resemble Saker Falcons even more. However, Sakers have a lighter top of the head and less clead head-side patterns. The Lanner's call is a harsh "wray-e".
The Lanner Falcon is a bird of open country and savanna. It usually hunts by horizontal pursuit, rather than the Peregrine's stoop from a height, and takes mainly bird prey in flight.
Wingspan of 95-105cm (3-3.5 feet)
The Merlin is the UK's smallest bird of prey, this compact, dashing falcon has a relatively long, square-cut tail and rather broad-based pointed wings, shorter than those of other falcons. Its wingbeat tends to be rapid with occasional glides, wings held close to the body. Its small size enables it to hover and hang in the breeze as it
pursues its prey. In winter the UK population increases as most of the Icelandic breeding birds migrate to our warmer climate. The UK breeding population is at the south-west extremity of the merlin's European range, and is thinly scattered across upland moorland from south-west England north to Shetland. In winter birds leave upland areas and come down to inland lowland and coastal areas. They can be seen in almost any open country but are often found near coasts. They can
be found at roosts in reedbeds, bogs and on heaths, often with hen harriers.
Wingspan: 2 feet (55-65 cm)
* The Owls (Strigidae)
Owls are not closely related to hawks or falcons. There is little written in classic falconry that discusses the use of Owls in falconry. However, there are at least two species that have successfully been used, the Eurasian Eagle Owl and the Great Horned Owl. Successful training of owls is much different from the training of hawks and falcons, as they are hearing- rather than sight-oriented (owls can only see black and white, and are long-sighted). This often leads falconers to believe that they are less intelligent, as they are distracted easily by new or unnatural noises and they don't respond as readily to food cues. However, if trained successfully, owls show intelligence on the same level as that of hawks and falcons