Tenectomy of the Supracoracoideus Muscle to Deflight Pigeons (Columba livia) and Cockatiels (Nymphicus hollandicus)

Abstract

Most of the methods used to deflight birds have one or more disadvantages, including impermanence, poor cosmetic appearance, or impairment of breeding function. We hypothesized that transection of the tendon of the supracoracoideus muscle at its insertion on the proximal humerus would impair a bird's ability to raise the affected wing and thus result in flightlessness. The purpose of this project was to evaluate the effectiveness of unilateral or bilateral surgical tenectomy of the supracoracoideus muscle in deflighting cockatiels and pigeons. Six pigeons (Columba livia) and 9 cockatiels (Nymphicus hollandicus) were included in the study. Three cockatiels were included in a sham group, and 3 birds of each species were included in a unilateral or bilateral tenectomy group. The birds in the sham group did not have flight difficulties at any time after surgery. Three cockatiels and 1 pigeon in the unilateral tenectomy group were flying within 3–6 weeks, respectively, after surgery. A ligament instead of a tendon was inadvertently transected in 2 of the pigeons in the unilateral group. These pigeons were able to fly the day after surgery. We did not euthanize these birds to confirm this suspicion. In the bilateral tenectomy groups, 1 of 2 cockatiels and 2 of 3 pigeons were eventually able to fly short distances within 4 to 6 months after surgery. In the same groups, 1 cockatiel died several hours after surgery and 1 pigeon was euthanized 6 weeks after surgery. The pigeon never regained its ability to right itself when placed on its back. Gross necropsies in both birds confirmed that the tendons of the supracoracoideous muscles had been transected. None of the birds undergoing unilateral or bilateral tenectomy had normal dorsal extension of the affected wing, but each was able to fly well enough to escape if taken outdoors. We concluded that neither unilateral nor bilateral supracoracoideus tenectomy is an effective technique for deflighting cockatiels or pigeons.