Talons at work during our Falconry Experience

Raptors possess incredibly sharp talons, which are crucial for hunting. The size and shape of these talons differ among various raptor species, adapting to their unique hunting styles and the type of prey they target.

For instance, falcons have long, slender toes and relatively short talons, which are ideal for catching birds in mid-air, think of casting a net. However, if the prey is too big to be caught, fast flying falcons can use their amazing speed to turn themselves into living bullets and, using their feet as impact weapons, knock their prey out of the sky. Falcons can thus kill their prey either with their initial high speed impact or by severing the spinal column with their specialized beaks.

In contrast, hawks, owls, and eagles are equipped with short thick toes and robust, powerful talons designed for gripping and crushing. A red-tailed hawk, for example, can exert upwards of 200 pounds of pressure per square inch with its talons. Hawks, owls and eagles kill their prey by using their powerful feet to crush it or puncture vital organs. Eagles demonstrate an even more formidable grip, capable of exerting on average 400-800 PSI.

Lanner Falcon

Red Tailed Hawk

Eurasian Eagle Owl

From left to right: talons belonging to a falcon, a hawk and an owl. Photos: George Adkins

How can such extreme grip strengths be achieved by birds that weigh between 1 and 15 lbs? A closer look to birds' leg anatomy and tendon system reveals a specialized mechanism that explains how a raptor's deadly grip is actuated and can be sustained for the time necessary to completely subdue its prey.

Perching reflex and tendon locking system

While talons are essential to hook the prey, a raptor's grip strength primarily originates from higher leg muscles. These muscles are connected to strong tendons that extend down to the toes, which are crucial for grasping and maintaining grip.

When a bird's foot finds a perch, or a prey, its toes curl around it. This occurs as the bird bends its knees and ankles, stretching its flexor tendons, which in turn retracts the toes and lock them in place. This mechanism, known as the perching reflex, allows birds to perch without expending excess energy. To release its grip and fly or walk away, a bird must first straighten its knees and ankles.

The tendon locking system assists in maintaining and increasing the lock. Several bird species (and bats) have adapted tendons and tendon sheaths with ridges and pleats that connect by sliding one on top of the other only when the toes are curled. This system helps to lock the bent toes in place, functioning much like a ratchet or a zip tie.

In raptors, the perching reflex and tendon locking systems, combined with razor sharp talons and strong leg muscles, create a ratcheting system that requires minimal energy to lock in place.

All bird photos taken by George Adkins during our Falconry Experience in La Jolla. Thank you George!

If you want to learn more about differences between falcons and hawks and see their adaptations in person, join one of our Group Experiences or Private Experiences on the beautiful cliff of La Jolla.