Exercising Raptors Back to Health

By Jennifer Guess, Senior Wildlife Technician

Photos by Jenn Guess

Here at California Wildlife Center (CWC) we see a lot of raptors with severe injuries that require many weeks even months of rehabilitation. The raptor family includes all types of hawks and owls. As the birds heal inside the ICU they do not get the daily exercise they would receive in the wild. Due to most raptors lengthy recuperation period, the vast majority need to be exercised at the end of the rehabilitation process to build up flight muscles before they can be released back into the wild.

When a raptor reaches the point in his recovery plan where he is stable and in good body condition he can be moved into one of our large outside aviaries. Raptors fly many miles every day and it is difficult to provide enough space in an enclosure where a bird can get adequate exercise on his own. One method of exercising raptors is to encourage them to fly from one end of the enclosure to the other. The drawbacks of this method is that it can be stressful on newer patients sharing the large flight aviary, and on patients in nearby flight aviaries. Plus, most birds learn very quickly how to navigate the enclosure with as little exertion as possible.

At CWC we use a method of exercising called creancing. During creancing the raptor is caught up from the outside aviary. A hood is placed over the head and eyes to reduce the stress level of the bird. Leather anklets are attached to the bird’s legs, above the feet. The bird is then transported to a nearby open

field. Leather strips, called jesses, are fed through the anklets and hang down below the bird’s feet. A light weight line with a weighted tube is connected to the jesses.

When everything is ready to go, the hood is removed and the bird is let go and he takes flight. He flies across the field and when he reaches the end of the line the weight in the tube starts to add resistance. As the bird drags the weight, he quickly tires out and lands on the ground.

It is important to do a lot of prep work before creancing a raptor. The weight of the tube must be adjusted depending on the weight of the patient. If the tube is too heavy, it could cause injury to the bird when he reaches the end of the line. If the tube is too light, the bird might be able to fly further than expected and into an obstacle like a nearby tree. The line must also be carefully measured before each creancing session. It should be long enough so the patient can gain lift and propel forward before feeling the weight of the tube but it should not be so long that the patient can reach obstacles.

During the flight, important information is being collected. The majority of our creancing is performed by Malibu resident and longtime CWC volunteer, Diana Mullen. She takes careful note of how far each patient flies, how much lift they are able to obtain, whether the wings are symmetrical during flight, and how quickly the bird tires out. She works very closely with our veterinarian, Dr. Duane Tom, and knows the history of each patient before taking them out for creancing. It is important to not push the patient too hard. Sometimes a single flight is enough for a creancing session. Depending on the patient, a bird might have three or four flights in a session. Each piece of information is carefully recorded in the patient’s record so Dr. Tom can adjust their individual plans. Volunteers are able to assist Diana during these creancing tests and all agree that seeing the raptors soar into the air serves as an excellent reminder of why we do the hard work of rehabilitation for these beautiful animals.

Being an Intern at CWC

By Luis Vasquez, Seasonal Animal Care Intern

Luis Vasquez
Photo by Alyssa Schlange

If you are blessed with the time and opportunity and have a little voice inside questioning whether you should intern at CWC or not, DO IT. It is incredible how much you will take away. I interned at CWC for 10 weeks this summer and it was wonderful learning about how to care for injured or orphaned animals, the differences between species, and the overall importance of wildlife rehabilitation.

When animals come into CWC, wildlife technicians, with the help of interns, assess the patient’s condition and create a treatment plan. From there, patients are monitored every day. This includes feedings (meal prep, assisted feedings), medicating, and providing behavioral enrichment (to stimulate behaviors they would have in the wild).

As an intern, I had the responsibility of helping determine when the animals showed significant improvements to be moved out of isolated care to larger group enclosures, and finally to be released. For example, one American Crow came in as an orphan during my first week. Throughout the length of my internship, the technicians and I helped with his unfortunate digestive issues, parasites, and cough. He went from isolated care, to a fledge pen, to our fledgling crow aviary. Finally, after 9 weeks, he is a juvenile crow and is in Pelipen [a large flight aviary] with the rest of our orphaned juveniles, where he is strengthening his flight so that he can soon be released.

Personally, this experience has helped me develop a preference for working with wildlife versus domestic animals in the future. In addition, the people you get to work with are awesome. I treasure them. They owed me nothing, yet stood by me in light of my clumsiness, awkwardness, and mishaps in an effort to advance my knowledge of wildlife. Thank you, from the bottom of my heart, for letting me be part of the Center’s common denominator: assisting in the well-being of California’s wildlife.