Peregrine Falcon Requires Change in Treatment

Nov 4, 2015 / Student Blogs

peregrine falcon

The Wildlife Medical Clinic is currently caring for a very uncommon patient—an adult peregrine falcon. This bird was admitted with fractured major and minor metacarpal bones, sometimes called the carpometacarpus. These bones are equivalent to the long bones in your hand, but birds only have two instead of five. Luckily, the fractures were far from the carpus (wrist); this is important because breaks close to or involving joints often affect the range of motion and long-term function of the joints.

Because the bone we were hoping to fix (the major metacarpal) was less than two inches long and about the width of a pencil, our repair options were somewhat limited. In the end, we decided to place pins perpendicular to the bone both proximal (before) and distal (after) to the fracture. We then reduced the fracture (attempted to physically put the bones back in a normal position) and connected the pins using an acrylic bar. This effectively held the bones in a more normal position and limited movement of the fragments while the body worked to form a callus and heal.

peregrine x-rayPost-op, everything looked good; the bird was holding the wing in a normal position and even eating. Unfortunately, within a couple of weeks (too soon for the bone to be completely healed), the peregrine started to pick at the skin around the fracture site. This cued us in that there might be something wrong with one of the pins, either that it was painful or felt strange (which can happen with nerve damage). After repeat radiographs and a physical assessment, we determined that one of the pins had become loose and was probably moving around in the bone and causing pain. Replacing the pin wasn’t an option because of the small size of the bone, so we elected to remove all of the pins early and try to keep the falcon calm and undisturbed for the next week while the bone continued to heal. Fortunately, he is a fairly stoic bird, so he rested and didn’t move the injured wing much during this critical period. The picking stopped, the skin is healing, and the fracture is almost completely stable. The bird will be leaving the hospital soon for flight reconditioning, and we hope to see him released by the spring when the rest of his species returns from migration.

Peregrine falcons are remarkable hunters, and their primary source of food is other birds. They will often search for food from great heights; when a meal is spotted, the falcon will fold its wings and dive hundreds to thousands of feet, reaching speeds of up to 200 miles per hour. The hunter will then grab its prey or simply strike it with its feet. The impact of a strike from that height and speed is often enough to stun or kill the prey outright. Peregrine falcons were once on the brink of extinction, but with pesticide bans and reintroduction efforts, the species has bounced back and can once again be found all over the world.

Do you have questions or comments? I’d love to hear! Post to the Wildlife Medical Clinic account on Facebook or Twitter @WildlifeatIL.

Nicki Rosenhagen, DVM