2016-07-14 / Pets
Helping raptors fly again
COMMENTARY /// Wildlilfe care
These may not be words you hear every day, but they are the basis for the important work that volunteer Diana Mullen does for the California Wildlife Center at its facility in Calabasas.
Creancing and imping enable the center’s staff and volunteers to rehabilitate birds that arrive with serious feather damage.
Creancing, basically flying the bird on a leash, allows recovering raptors to exercise and build their flight muscles before they are released.
Imping is the repairing of a bird’s flight feathers, which could range from replacing a few missing wing or tail feathers to replacing them all.
While they are recovering from whatever injury brought them to the center, the birds lose muscle strength and mobility. They need be exercised to return to optimal, releasable health.
To exercise a raptor, Mullen first fastens leather anklets to the bird’s leg. To the anklet, she attaches a line, a creance, that is 100 to 200 feet long, connected to a weight.
The bird does many practice flights, tethered by the line. These sessions continue until the bird displays strong flight capabilities.
Mullen ensures that the bird can gain altitude, turn in both directions, show flight symmetry, lift and power before recommending its release to the veterinarian. It’s vital that each animal be able to both protect itself and hunt for its own food before it is returned to the wild.
California Wildlife Center frequently takes in birds that are missing vital flight feathers. A bird can lose feathers for a variety of reasons, including an attack by predators and accidents with cars or electrical lines.
There are two options for a bird that lacks the wing and tail feathers needed for flight: keep the bird until it molts and new feathers grow in, or, if the bird is a good candidate, a veterinarian at the center can attach a new set of feathers in the process called imping.
Donor feathers—either collected during a molt or harvested from a deceased bird of the same species—are collected all year long at the center. When donor feathers are harvested, they are kept in the exact order in which they are removed and reapplied in the same order.
Mullen got the word that a red-tailed hawk in Hollywood was unable to fly. When she reached the bird, she said, it was “the saddest bird and in the worst condition” she had ever seen. When she picked it up, Mullen said, it was like picking up a handful of leaves.
The bird was starving and extremely dehydrated, with severe damage to its wing and tail feathers.
The bird was given IV fluids and was hand-fed until it returned to a healthy weight. At that point, staffers decided the bird was a good candidate for imping.
An appropriate set of tail and wing feathers was found and the process began.
The bird was sedated, and CWC veterinarian Dr. Lorraine Barbosa removed the remains of the damaged feathers.
Donor feathers were inserted into each empty feather shaft and affixed with a flexible epoxy. When the bird molts, the donor feathers will be completely replaced.
Once the imping was completed, the Hollywood hawk had a brand-new set of wing and tail feathers.
At first it seemed puzzled at the weight on its wings; it had not had a full set of feathers for quite some time, and it had lost all of its flight muscles.
The hawk is now ready to begin its creancing sessions to build up its flight muscles and cardiovascular stamina to prepare for release.
Last year the wildlife center received 146 hawks, 48 of which were red-tailed hawks like the one that Mullen rescued.
The California Wildlife Center on Malibu Canyon Road near Calabasas is a registered nonprofit organization funded through individual and foundation donations. For information, visit www.cawildlife.org.