Feather Transplants through Imping

In our Raptor Hospital, we always try to keep our birds in perfect feather condition, but sometimes feather damage is difficult to prevent during rehabilitation. While recovering from emaciation, Patient #26380, a young Cooper’s Hawk, broke her tail feathers and several primary flight feathers. These feathers are essential to flight by giving lift, forward thrust, drag, stability, control, and steering, and without them, she wouldn’t be able to fly or survive on her own. To prepare her for release, we performed a practice called imping.

All birds regularly undergo a natural process called molting in which old feathers are shed and replaced by new feathers. Cooper’s Hawks typically go through one complete molt every summer, meaning that our patient would need to remain in our care for nearly a year to wait for her next molt. Luckily, we can perform an ancient falconry technique called imping to manually replace broken feathers with donor feathers. Like human hair and fingernails, feathers are dead structures made of the protein keratin, making it a painless process for the bird.

The earliest reference to imping was in a book written in the 1240s, “The Art of Falconry,” by the Holy Roman Emperor Frederick II of Hohenstaufen. While modernized, the process used at Carolina Raptor Center is essentially the same and, while simple, it requires expertise and skill to choose the correct donor feathers and properly connect them.

Step 1: The damaged feathers are clipped at the base of the feather shafts

Step 2: The donor feathers are selected by matching the size (length and width) to the patient and matching the donor feathers to each other. Each feather performs a slightly different job and is shaped slightly differently.

Step 3: Small drill bits are used to remove the pith and hollow out the inside of the feather shaft stubs and donor feathers to create space for the next step.

Step 4: Imping needles are created by whittling bamboo skewers which are used to structurally connect the feathers. Each imping needle must be custom-made to an exact fit for both the feather stub and the donor feathers.

Step 5: The pieces are assembled without glue to ensure the length and orientation are correct

Step 6: Using a quick-drying epoxy, the imping needles are glued into the donor feather

Step 7: The imping needles are glued into the feather shaft stubs

Step 8: Release! Luckily this procedure allowed our Cooper’s Hawk to rapidly return to full flight ability and she was released in Huntersville on September 6th! She will keep the donor feathers until her next molt, when the imped feathers will be replaced by her own brand new feathers.