Bald Eagle | ID | Size | Wingspan | Talons | Juv. Bald vs Golden Eagle
This brief overview addresses common questions about the bald eagle’s talon form, length, adaptations, and strength.
The majestic bald eagle is familiar to many and revered by ancient cultures. Its talons’ power and strength have been associated with superlatives that may not accurately represent America’s National Bird.
In this article, I attempt to expand, clarify, and respond to what has been written about the bald eagle’s talons.
Do Bald eagles have talons or claws?
A common question is whether bald eagles have talons or claws.
A quick review of the literature suggests that claws and talons are basically the same in composition, form, and most functions. Technically, mammals, reptiles, and birds have claws of very similar appearance.
But, the claws of a bald eagle, and other birds of prey, are called talons.
This is to say that only birds of prey have talons while other animals, including non-birds of prey, have claws. For instance, we say the claws of a duck or a dove, never the talons of a duck or a dove.
Talons and claws are also the same in composition. They are both made of keratin, which is the same hard protein that makes human hair. Talons and claws can be seen as compressed and hardened human hair.
Difference between the function of talons and claws.
The only apparent difference is that talons are used to grab and carry things. Claws have many similar functions as talons but are not used to grab and carry things.
Birds of prey use their talons to trap and carry their prey, nesting material. They seldom use their beak to carry their prey or other things.
On the other hand, mammals, reptiles, and other non-birds of prey use their claws to climb, run, dig holes in the ground, and even capture their prey but cannot carry or transport their prey or other things with their claws. They tend to carry things with their mouths and beaks.
A bald eagle has 8 talons.
A bald eagle has four talons on each foot. The talons start as gray in nestlings but turn black by the time the eaglet leaves the nest. The talons never change color for the rest of the eagle’s life.
Three of the toes and talons point forward, while one points backward or in the opposite direction (See photo above). The back toe is known as “hallux” and has a similar function as a thumb in humans. The hallux allows birds of prey to grab and carry their prey with their feet.
How do eagles use their talons?
The talons are the most important part of a bird of prey’s body. It is their hunting tool that raptors depend entirely on for survival.
Eagles use their talons to capture, subdue, and kill their prey. Eagles and other birds of prey also use their talons to hold the prey down while tearing small pieces of meat with their beak.
Besides serving as the most important hunting tool, eagles also use their talons as weapons to attack other birds and animals, defend their territories, and fight over resources such as food and mating partners.
Eagles also use their talons to transport nesting material, perch on branches of different sizes, and groom themselves.
Some eagle species, including the bald eagle, use their talons to lock with another eagle’s talons in mid-air; then, both eagles drop vertically in a spiral fashion. This is an aerial display that male and female eagles perform during pair formation.
The size of a bald eagle talon.
The bald eagle is one of the largest birds of prey in North America and has some of the largest talons. The golden eagle is very similar in size and has similar talons.
The California Condor is the largest flying bird in North America, but it is a carrion feeder. Hence its talons do not have the same function as birds of prey that hunt live animals.
The 8 talons of the bald eagle are of different sizes and vary in shape. A team of ornithologists (1) took measurements of talons on many bald eagles. They determined that the hallux (digit I) is the largest and strongest talon, followed closely by the digit II talon (inner toe). The talons of digits III and IV are considerably smaller.
The size of talons I and II are adapted to the bald eagle’s hunting strategy and handling of its prey. The function of talon I is gripping a prey against the front talons. Simultaneously, the eagle uses talons II on opposite feet to grip and transport its prey.
Talons I and II of each foot function as the main tools, while talons III and IV’s, middle and outer talons, have only a supporting role. Some ornithologists call the outer talons accessory talons.
The following table shows the length, chord, and depth of a bald eagle’s talons.
Type of Talon | Part of Talon | Measurements in inches |
Digit I | Length | 2.1 |
Chord | 1.3 | |
Depth | 0.4 | |
Digit II | Length | 2.1 |
Chord | 1.2 | |
Depth | 0.4 | |
Digit III | Length | 1.7 |
Chord | 1 | |
Depth | 0.3 | |
Digit IV | Length | 1.5 |
Chord | 0.9 | |
Depth | 0.3 |
There is a good deal of variation in the length of bald eagle talons. As a general rule, larger birds have longer talons. Female bald eagles are always larger than males and have larger talons.
The bald eagle’s right and left legs below show the difference between the hallux and outer talons. See the difference in size between DIGIT I and DIGIT IV of the left leg below. Also, notice the difference between the DIGIT II Inner Talon of the Right Leg and the DIGIT IV Outer Talon of the left leg.
Bald eagle feet and talon adaptations.
The eagle’s talons are adapted to catch and handle fish, which constitutes this bird’s main food source. For such purpose, the hallux and talon of digit II have evolved into larger and more hooked than the middle and outer talons.
While not a talon adaptation per se, the bald eagle feet have little bumps on the “palm” of their feet that help to secure slippery prey like fish.
What is really the strength of a bald eagle’s talon?
The pressing power numbers given for the bald eagle may have been exaggerated.
To get to a more accurate bald eagle’s pressing power number, I compare other raptors’ known pressing power with their hunting behavior and prey choice.
A bird of prey’s toe configuration, talon shape, length, and associated leg, feet, muscles, and tendons results in the perfect grabbing, stabbing, and crushing tool that fits its hunting behavior; this is the result of millions of years of evolution.
The pressing power numbers assigned to familiar birds of prey found on the internet come from largely uncited sources.
The table below shows the pressing power in pounds per square inch (psi) of a few familiar birds of prey.
- Golden Eagle: 400 to 791 psi.
- Bald Eagles: 700, 823, and even 1000 psi.
- Harpy Eagles: 530 to 598 psi.
- Philippine Eagle: higher than 500 psi.
- Great Horned Owls 500 psi.
- Red-tailed Hawk: up to 200 psi.
The pressing power assigned to the bald eagle may be elevated given its hunting behavior.
The great-horned owl and the golden, Philippine, and harpy eagles hunt small and medium-size live animals that they must quickly subdue and kill before they exert damage on the hunter. These birds of prey kill by pressing their talons into their prey, causing internal damage that results in death.
In contrast, the bald eagle picks dead or dying fish floating near the surface of the water, supplementing its diet with meat from carcasses. The bald eagle does not really need substantial talon strength or pressing power to pick up and transport dead or dying fish.
HawkQuest, an environmental education nonprofit in Colorado, measured the power grip of the bald eagle. Their findings indicate that America’s National Bird has a powerful grip of about 400 psi.
Other sources with a limited scientific basis indicate that the bald eagle can exert a grip pressure of 300 psi.
It is more likely that the bald eagle has a grip pressure between 300 to 400 psi.
Questions about the bald eagle’s pressing power.
Some of the common questions include whether a bald eagle can crush a human skull, kill a human being, or kill a dog or a cat.
The sheer size and talons of a bald eagle have the potential to hurt humans and other animals. An impact between a bald eagle flying at full speed and a human being, cat, or dog could certainly cause serious damage or even death.
But an attack and impact at full speed are improbable to happen. A bald eagle’s hunting behavior is geared toward finding still or barely mobile food items. Adult eagles may hunt small waterfowl and mammals, but that is as far as they go in terms of capturing and killing live prey.
Unlike other raptors, bald eagles are not aggressive to research biologists who examine their eggs and chicks on the nest for scientific purposes.
So, a bald eagle does not have the pressing power to crush a human skull nor the type of hunting behavior that would enable it to kill a large cat or a dog.
Conclusions:
Claws and talons are often used interchangeably. While claws and talons are similar in appearance and have many similar functions, talons are used to grab, press, hill, and transport prey and other things.
Only raptors or birds of prey have talons. Other birds are unable to use their claws to carry their prey as birds of prey do.
The 8 talons of a bald eagle are the bird’s main hunting tool. Talons have different sizes on each foot and have different roles during the hunting and handling of the prey.
Some of the powers attributed to the bald eagle’s talons may have been exaggerated.
References:
(1) Appleton, Avery J., R. Christopher O’Brien, and Pepper W. Trail. “Species Identification of Golden and Bald Eagle Talons Using Morphometrics.” Journal of Raptor Research 50.1 (2016): 76-83.
LEARN MORE: