February 20, 2022

What is a bird of prey?

February 20, 2022/ Deborah Brazendale

What exactly is a ‘bird of prey’? It’s an odd name, when you think about it, isn’t it? (Even odder when you see it misspelled as ‘bird of pray’.) It’s a question that comes up a lot in our bird-of-prey and owl experiences, so let’s explore what is meant by a bird of prey.

The short answer is that a bird of prey eats meat; it is a predator that must hunt and eat other birds or animals to survive. Whilst lots of birds eat invertebrate animals such as insects and worms, birds of prey typically take larger vertebrates such as small mammals and other birds as their prey. A distinguishing feature of birds of prey is the fact that they use their feet (and sharp talons) to capture and carry their prey away and they have a hooked beak to kill and break into their prey. Most birds of prey hunt live prey but some species, like vultures, will also eat carrion.

Which birds are (and are not) birds of prey?

Birds of prey can be broadly separated into three (unrelated) groups: acciptrifoformes, which include eagles, buzzards, hawks, ospreys and harriers, the falconiformes (falcons), and the strigiform, which are the owls. In general, owls are nocturnal hunters while the others are all diurnal (daytime) hunters. There are around 300 species of acciptrifoformes and falconiformes and just over 200 species of owls.

Not all birds that hunt and eat other animals are birds of prey. Although birds like magpies, herons, gulls, penguins and storks are predators and eat other animals s

uch as songbirds, fish or frogs, they are not classed as birds of prey because they don’t have the distinguishing features of a bird of prey.

Harris hawk preparing to land - feet out

What are the distinguishing features of a bird of prey?

Across the species (eagles, buzzards, hawks, falcons and owls), birds of prey will have distinct and particular features that give them their apex hunter’s advantage. These features include wing shape, flying style and speed, feather colour and type, manoeuverability, leg length and more, but - because of how they hunt and kill - all birds of prey have powerful feet and a strong, hooked beak.

Harris hawk. Image by Jon S Pow Photography

Sakr falcon. Image by Jon S Pow Photography

In eagles, the feet are very large and can exert very high pressure. A bald eagle, for example, has the strength to apply 400 pounds per square inch (psi) of pressure in its enormous feet, which is ten times the grip of an average adult human. The golden eagle’s prey can include mammals the size of a roe deer or fox, so their feet and talons need to be capable of a strong grip for lifting and carrying away that kind of weight, as well as the killer pressure needed to crush mammal bones.

In the images above, you can see the impressive feet on Altai, our golden eagle. Steve’s falconry glove is triple thickness to protect his arm but, even so, if Altai decides to apply pressure, Steve knows about it! To give you an idea of his size, Altai’s talons alone are each around 5-7cm long…

Falcons catch their prey on the wing, or in mid-flight, so they need to have feet that can bind to their quarry and hold on to it but they also need a quick method of killing their prey before it wrestles free in the air or damages them in the process of struggling to escape. The hooded beak of a falcon includes an extra serrated bit on the upper part of the beak. It looks like a notch - a rough edge - and its known as, a ‘tooth’, specifically a tomial tooth, which is used a little like a can opener. Falcons and (kites) use this tomial tooth to quickly kill their prey by snapping the vertebrae. You can see it in the image below, on Logan’s upper beak.

Peregrine falcon and tomial tooth — LOGAN our peregrine falcon showing his tomial tooth.

The two photos below show off the falcon’s tools of the trade: hooded beaks, powerful feet and strong, sharply pointed wing tips, giving them the aerodynamic profile they need to cut through the air at high speed.

Young tiercel (male) peregrine

A jack (male) merlin

Another feature of birds of prey that makes them different from other birds and most other animals is that the males are smaller than the females, which is known as reversed sexual dimorphism.

In most vertebrates, and in non-predatory birds, the male is typically larger than the female. However, in birds of prey, the female is larger. The most noticeable size difference is in falcons and hawks - in some cases (the kestrel, for example) the female is larger than her male counterpart by as much as 50%.

Ailsa, our female eagle owl (right) weighs approximately 6.5lbs (2.9kg), while Fergus, our male eagle owl, is just 4lbs (1.8kg) - almost 50% lighter!

The size difference between sexes is much less obvious in birds of prey that predate on slower species. Vultures, for example, which rely on team work or others’ left-overs (and carrion) to be able to eat, have little size difference between the sexes.

There are several theories as to why birds of prey have reverse sexual dimorphism. These include the suggestion that males and females can more easily share territory if they are different sizes: birds of the same species will not be in competition for the same prey if one is significantly smaller / larger than the other. And perhaps a female’s need to produce and spend time incubating eggs accounts for her larger size - she needs larger reserves of energy.

Is a raptor different from a bird of prey?

No, raptors and birds of prey are the same thing. The Victorians called birds of prey raptors, from a Latin world meaning to plunder or take by force. This perfectly describes a bird of prey’s hunting style, which is to ambush its prey and then carry it off to a safe place to eat. (The term ‘raptor’ is also used for the group of dinosaurs known as Dromaeosauridae, the feathered lizards that include the Velociraptor made famous by the film ‘Jurassic Park’. Scientists are yet to confirm a direct evolutionary link between these bird-like dinosaurs and the birds of today, but they certainly share the same design of powerful feet and fierce talons as our birds of prey. )

What birds of prey can be found in Scotland?

There are 14 species of diurnal (daytime-hunting) raptors (falcons, hawks, eagles) and 4 nocturnal raptors (owls) in Scotland.

The diurnal Scottish birds of prey are: red kite, honey buzzard, common buzzard, goshawk, sparrowhawk, merlin, kestrel, golden eagle, white-tailed (sea) eagle, osprey, hobby falcon, peregrine falcon, hen harrier and marsh harrier. Below is a photo of Lewis, Steve’s goshawk on a pheasant kill. In it you can see his hooked beak and sturdy, powerful legs but his feet are covered in the pheasant’s feathers.

The nocturnal birds of prey found in Scotland are: barn owl, tawny owl, short-eared owl and long-eared owl.

The barn owl’s feet, used with such precision to capture thousands of voles and mice in a year, are covered with tiny feathers to minimise the sound of the air passing over them, allowing the owl to fly almost silently, in order to surprise its unsuspecting prey.

Eagle owls are now also to be found living wild in Scotland (having escaped from captivity) and Snowy owls are sometimes seen on the islands of the Outer Hebrides, but neither species is considered native.

Eagle owl demonstrating an attack - feet first!

Barn owl hooded beak and feather-covered feet

Want to know more about birds of prey?

I’ve included some reference below but I’m confident you’ll learn the most and get the most out of booking an experience with Steve!

In The Scottish Countryman’s team, we have a barn owl and two eagle owls, a golden eagle, falcons and hawks. You can get up close to and learn more about each of these birds in our bird of prey experience or owl experience. Steve explains each of the birds’ ‘super powers’ and demonstrates their hunting/flying styles for you so that you can really appreciate the specific distinguishing features that make them all such superb birds of prey.

Sources

Links to related posts on my site

The Scottish Countryman recommends

July 23, 2018

The white-tailed eagle

July 23, 2018/ The Scottish Countryman/ Deborah Brazendale

How many birds of prey can you name that you can see in the wild in Scotland? Six? Maybe twelve? Perhaps more?

Although perhaps most famous for its peregrine falcon, it may surprise you to know that Scotland is home to more than 20 varieties of bird of prey. This series introduces you to some of the birds of prey that you can see across Scotland. This post: the white-tailed sea eagle.

May 24, 2018

The merlin

May 24, 2018/ The Scottish Countryman/ Deborah Brazendale

How many birds of prey can you name that you can see in the wild in Scotland? Six? Maybe twelve? Perhaps more?

May 03, 2018

Where do your birds come from?

May 03, 2018/ The Scottish Countryman/ Deborah Brazendale

Sourcing birds of prey for Inspired Falconry

If you've been following our series on what birds of prey can be seen in Scotland, you'll know that more than twenty species of raptor can be found in Scotland. Yet none of these are ever going to end up in the Inspired Falconry team, or - for that matter - any other team.

Why?

Under the Wildlife and Countryside Act of 1981, it is illegal to remove any bird from the wild. Eggs, nests, birds and their habitats are all covered by the Act to ensure that our native species can thrive.

So how do falconers like Steve get their birds of prey?

The answer is that all of the raptors used in falconry in the UK today are either captive-bred in this country or imported under licence. Birds of prey bought from these breeders must come with the necessary legal paperwork, which - depending on the bird and its status under the law - may simply be confirmation of origin or an Article 10, which is like a passport for a bird. The Article 10 paperwork, for 'Schedule 4' endangered birds (9 of them, including the peregrine, merlin and golden eagle) contains information about the bird's parents and is matched with a numbered ring on the bird's leg. The Government Department for the Environment, Food and Rural Affairs (DEFRA) oversees this registration process.

British captive-bred stock may stem from wild-captured birds taken under licence or before the 1981 Act. Birds are bred in captivity by dedicated, skilled falconers and breeders who have learned to replicate nature as closely as possible in order to achieve any success.

Why and how did captive-breeding start?

Captive breeding was initially a reaction to raptor population devastation caused by pesticides such as DDT in the 1950s. Changes in farming practices (enabled by pesticide use) and the effect of the poisons themselves decimated bird numbers during the 1960s. Prey species were drastically reduced in number and diversity and raptors' eggs were damaged by the pesticides, preventing their shells from developing properly. Raptor numbers declined sharply. Starting with peregrines, a small number of falconers set out to breed them in captivity, helping to save and then strengthen the population over time.

Captive-bred birds can be released successfully into the wild, using a process called 'hacking', which we'll cover in another post.

The network of UK's falconers and their mutual interests and interactions means that birds are now routinely exchanged or sold between them, depending on need and circumstances. Where a falconer can no longer provide a bird with the hunting grounds or secure mews it needs, another falconer will take on the bird instead. Some birds live for many years and may be retired from a breeding programme or from hunting, living out their days in more sedate places such as Falconry Centres, Owl Sanctuaries and Safari Parks across the UK.

Those of you who remember Peggy, our peregrine (pictured above), may recall that she was a retired breeding bird. You can see from her really dark colouring that she's a mature female. Ailsa the Eagle Owl (below), on the other hand, was only about 4 years old (and called something else) when she was bought by Steve from friends who could no longer fly her every day.

How much are birds of prey?

Not that you'd ever want to buy one, unless you were highly experienced or properly trained and had the appropriate set-up, but we're often asked how much the birds are worth. The rather unsatisfactory answer is that it depends. It depends on the quality, gender, rarity, and training; it depends on the breeder and the birds' availability! It depends on what they are used for and how old they are. But, as a broad example, a mature, trained female Golden Eagle would fetch anywhere from £5,000-£7,000, whilst a male Barn Owl can be found for under £100. The cleaning bills and food preparation are a whole other story, though!

No matter where they have sourced them, falconers like Steve are passionate about birds of prey and pride themselves in their husbandry and care. It takes many hours and needs daily input to keep a bird in peak condition. A bird's condition is evident - in their eyes, their feathers, their feet and their general demeanour. It certainly affects their ability to fly or to hunt. But that's another post for another day!

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