Welfare Assessment of Flight-restrained Captive Birds: Effects of Inhibition of Locomotion

Abstract

Morphological and physiological adaptations have allowed birds to utilize flying as part of the primary locomotion. However, birds in captivity are often deprived of this natural skill due to limited living space or wing
amputation. This article aims to investigate the essentialness of flight and welfare assessment of flight restraint in captive birds, using animal-based measurement. Ten wild-caught great mynahs (Acridotheres grandis) were chosen as test subject and evaluated in three separate studies. In pathology study, bird wings were partially amputated to assess possible neuroma formation at the site of amputation. The birds involved in this study were evaluated on day 20 and day 40 post surgery. We found that wing amputation did not result in neuroma formation. In ethology study,
spatial preference of the captive birds was evaluated by providing cages with different structures. We noticed that the birds indicated higher preference for spaces that were bigger or with higher vertical space with or without food provided. In physiology study, strength of pectoralis muscle was evaluated with electromyography in both wild birds and birds that were flight restrained for 40 days. The results indicated that strength of pectoralis muscle diminished significantly in birds with flight restraint. This research suggested that captive birds were still highly inclined to use
flight as means of locomotion, and provided useful information as to how enclosures of captive birds should be carefully designed for better animal welfare.