Are Owls Raptors? (An In-Depth Explanation)

The term “Raptors” typically describes diurnal predatory birds that use their strong gripping feet to attack other animals.

However, owls can see in the dark so they normally hunt during dark hours.

Still, owls use their muscular feet with piercing talons for hunting.

Which means,

Owls are often considered the nocturnal substitutes for classical diurnal raptors.

That said, even the so-called classical raptors are not from the same taxonomic orders or even single bird clade.

So, technically,

There is no precise scientific justification to even exclude owls from the classical raptors.

Besides, if raptors are just some diurnal predators that hunt with feet then, most insect-eating birds should be called raptors.

At this point, you may be confused, wondering:

What Is a Raptor Bird?

Currently, ornithologists don’t agree upon a singular definition for the term “Raptor”.

Therefore, all the existing raptor definitions sound somewhat like ambiguous opinions.

However, all scientific definitions have set criteria and assumptions.

Anyways, to simplify this entire discussion let’s start with the word raptor itself.

Now, the term Raptor originated from the Latin word “Rapere” meaning “to seize, to plunder, or to grasp”.

A raptor should be able to kill other birds using its feet.

But, most such attacks were observed in the daylight.

The predatory were larger than prey animals.

Most birders define raptors as “the diurnal large-sized predatory birds that crush prey animals using their strong grasp, or more precisely their feet”.

Even this definition is imperfect and has several flaws.

How so?

Because this definition can be used to describe nearly all birds, even songbirds.

To give you a clear understanding,

I present to you a table describing the common statements about raptors and issues with them.

Statement	Issue	Classical Example(s)
Raptors are predatory birds that eat other animals.	Since most birds eat other animals. Raptors should include nearly all birds. Insect-eating birds are also predators. Even nectar-eating birds feed insects and worms to their hatchlings.	Chickadees eat caterpillars. Robins eat earthworms. Gnat-catches eat gnats.
Raptors can eat only eat mammals.	Certain birds that are often described as raptors also eat fish, reptiles, amphibians, insects, and even vegetation.	Eagles mostly eat fish.
Raptors only eat vertebrates.	Certain birds have the ability to eat large mammals but they are not called raptors.	Shrikes have hooked bills and sharp claws. These even eat rodents and other animals. However, they are only called “Honorary Raptors”, and never true raptors. Auks, gannets, and terns feed entirely on fish. Herons also eat mammals, fish, amphibians, even carrion.
Raptors are large-sized birds that hunt other animals.	Certain raptors are extremely tiny but can still kill other animals. Several large-sized birds that hunt are not considered raptors.	The Collard Falconet can grow to only about 18cm and wei/ghs less than 100g. However, it is considered a raptor. Penguins are not perceived as raptors.
Raptors hunt using their strong feet.	Some raptors don’t use their feet for hunting.	Vulture feet are shaped like chickens they cannot use their feet for hunting.
Raptors hunt and fly away with their victims.	Raptor hunting styles vary greatly.	Vulture cannot take away their food. Owls prefer to eat on site.
Raptors are diurnal birds.	Several birds hunt at night.	Owls tend to prey at night.
Raptors only eat fresh meaty prey.	Certain raptors scavenge and others don’t ever eat meat.	Vultures scavenge days old carcasses. Palm-nut vultures eat decaying fruits and vegetables. Honey buzzards eat insects.

Now, this may have left you more puzzled than before.

But here is the thing:

Raptors are not part of a singular scientific group. They can only be described in terms of characteristics that most of these birds represent.

Generally, a bird is considered a raptor if it has the majority of the following characteristics:

Hooked sturdy beak.
Strong feet with sharp talons.
Keen eyesight, more powerful than even human eyes.
Carnivorous diet, mostly vertebrates.
Females are larger than males.
A low number of eggs per clutch

Even with these characteristics as a criterion, there is no exact way to justify a bird as a raptor.

Owls are often considered controversial raptors.

Are Owls Bird Of Prey?

Allegedly, they are.

This too depends on how you define owls.

You see, the term “raptor” is still somewhat specified for predatory birds that hunt using feet.

Birds of prey are supposed to include all those birds that eat other animals.

So,

Technically, even crows and sparrows are supposed to be birds of prey as they eat other animals especially worms.

That said, birds of prey were first used to describe bird members from the Order Falconiformes.

But, at that time, Order Falconiformes included Eagles, Hawks, Buzzards, and even Vultures.

Meanwhile, owls were classified in separate taxa.

Currently, Falconiformes primarily describe only falcons.

The terms “Raptors” and “Birds of prey” are often used interchangeably.

Still, birders try to distinguish the two groups by defining birds of prey as:

“Birds of prey are all those birds that can search and hunt for vertebrates.”

This does not specify a method of hunting using bird feet, or even a strictly mammalian diet.

Consequently, birds of prey are all those birds that are traditionally excluded from Raptors.

These include:

Skuas
Gulls
Penguins
Kookaburras
Storks
Herons
Shrikes
Phorusrhacids
Insectivorous songbirds

Technically,

Nearly all raptors are birds of prey, but all birds of prey may not be raptors.

Again, the term raptor is used synonymously with birds of prey.

Therefore, only raptors are mostly described as birds of prey.

Since owls fill some criteria for both raptors and birds of prey.

Regardless of the definition of birds of prey, owls should be considered birds of prey.

Now, you might be thinking that if owls are birds of prey, then:

Is An Owl a Raptor?

Technically, they should be raptors.

You see, owls display such predatory characteristics that classifying them as anything other than raptors seems unfair.

What characteristics?

Well, here are owl features that make them raptors.

Raptor Criterion	Owl Characteristic
Hooked Sturdy beak.	They do have small downward-pointing hooked and sturdy piercing beaks.
Strong feet with sharp talons.	Owl grip is the strongest among raptors of comparable size. Their talons are also the longest and probably, sharpest.
Keen eyesight.	Owl eyes are the largest for any bird of their size. They have the ability to see about 8-10 times better than humans. Also, they can even see in the dark.
Carnivorous diet, mostly vertebrates.	Owls hunt a variety of animals, mostly vertebrates.
Sexual Dimorphism	Female owls are larger than male owls.
A low number of eggs per clutch.	Owls have a relatively high number of eggs. However, most offspring don’t survive their first year. Therefore, even if the number of eggs is high, there are less number of viable babies.

Looking at this list, you may be confused as to why the placement of owls as a raptor is an issue at all.

Or, more precisely,

Why Are Owls Not Raptors?

Because owls occupy a separate order of birds from all other raptors and they also display abilities, unlike any other bird of prey.

Now, to fully appreciate owls as unique to other raptors, let’s compare a typical owl with a common raptor.

Criterion	Common Raptor	Typical Owl
Genetic Lineage	Most raptors belong to two somewhat related orders: Falconiformes and Accipitriformes.	Owls occupy a separate bird Order called Strigiformes.
Activity hours	Most raptors are diurnal and hunt during the day.	Owls are nocturnal predators that hunt during dark hours.
Hearing Ability	Most raptors have symmetrical ears that allow them great hearing ability.	Owls have exceptional hearing as they have two ears located at different heights to find a moving object precisely. Also, the owl face is structured to allow maximum sound waves within the ears.
Shape and size ratios	Most raptors have streamlined bodies with small heads and relatively large bodies.	Owls don’t have streamlined bodies. Also, owls have relatively large heads compared to their body size.
Eyes	Generally, raptors have large but round eyes located on either side of their heads. They have a high ratio of cone cells to rod cells. Therefore, most raptors can see sharp color attuned images during light hours.	Owl eyes are huge, cylindrical, and tube-like. The retina is reflective and their eyes contain a high number of rod cells to cone cells. Therefore, owls are colorblind but they can clearly see even in the dark.
Skeleton	Most raptors can move their head only about 90 degrees. A typical raptor has four toes arranged as three in front and one in the back, giving a solid grip.	Owl bones are structured to allow their heads a rotation of 270 degrees. Owl feet also contain four toes. However, the owls can use their feet in two arrangements: Three toes in front and one in the back. Two toes in front and two toes in back. This shows that owl feet bones and muscles are different from an average raptor.
Brain Ability	Most raptors have moderate-sized brains and therefore, a moderate judgment ability.	Owl brains are so small as to only allow primary functions. Therefore, owls have only a limited ability to think and judge.
Hunting Style	Most raptors hunt during the day and take their prey to somewhere safe for eating.	Owls hunt in the dark and eat their prey on the spot.
Feather and Flight	Most raptors have sleek broad feathers to allow them to soar on thermals. These can turn themselves into tear-drop shapes to achieve great speeds.	Owls have thick downy feathers that are serrated enough to allow silent flight. The wings only permit short bursts of speed.
Nesting	Most raptors build their own nests or use an abandoned nest. Otherwise, lay eggs on the ground.	Owls typically steal nests of other birds.

Are Owls Part Of The Raptor Family?

Well, Owls deserve to be called a part of the Raptor Family.

Why?

Because owls innately have all the raptor family traits.

So, owl being part of the raptor family is still not as controversial as some claiming that “Theon Greyjoy deserves to be called a Stark more than Greyjoy”.

The issue started when Carl Linneus classified birds for the first time.

At that time, all supposed raptors were put in the same order as shown in figure 1.

However, the owls were the first to be removed from this system and put into a separate order, mainly because owls were nocturnal predators.

But back then, these birds were still called raptors.

To date, the issue to classify owls as raptors, remains.

Are Owls Raptors?

Figure 1: Carl Linnaeus Classification for Raptor Birds

That said, I postulate three valid reasons to call owls raptors:

a. General Perception

Currently, the term raptor is ambiguous. However, it is often used for birds of prey. Also, owls are often discussed in journals and laws relating to raptors.

We can claim that:

Owls are raptors because they are commonly perceived and discussed as raptors.

b. Term Raptor

Since the literal meaning of raptor refers to a bird that can capture prey using its talons.

Owls have every right to be called raptors.

c. Scientific Definitions

In 2019, scientists tried to clearly define raptors.

For this, eight experts used DNA studies that suggested that land-bird groups of predatory birds evolved from a common ancestor.

Or say,

All land raptors had a common starting point.

So, Christopher J.W and his colleagues published a paper in the Journal of Raptor Research that defined raptors as:

”All species within orders that evolved from a raptorial land bird lineage and in which most species maintained their raptorial lifestyle as derived from their common ancestors.”

Sounds complicated? That’s academia for you, genius and extremely specific.

Practically, this means that owls are indeed raptors.

But this also suggests that five other bird orders are also raptors.

What Are The 5 Raptors Birds?

By all current definitions, the following five bird Orders contain raptor species.

These include:

	Raptor Groups	Bird Families	Remarks	Raptor Members
1	Accipitriformes	Accipitridae	The most prominent raptor group. Small to large birds with variable diet, but hooked bills and forward-facing eyes.	Hawks (Buteos & Accipiters), Eagles, Old-World Vultures, Kites, Harriers.
		Pandionidae	Often called “Fishing Eagles” or “Seahawks” as they eat marine food.	Ospreys
		Sagittariidae	Ground-dwelling birds.	Secretarybird.
2	Falconiformes	Falconidae	The swiftest raptors.	Falcons
3	Cathartiformes	Cathartidae	The most developed sense of smell for any bird.	New-World Vultures
4	Strigiformes	Strigidae	Large and round heads, muted feathers, and short tails.	True Owls
4	Strigiformes	Tytonidae	Heart-shaped large heads and long legs.	Barn-owls
5	Cariamiformes	Cariamidae	Long-legged ground-dwelling birds.	Seriemas