An Open-Door Policy: How Removal of a Visual Barrier Improved Welfare in Zoo-Housed Bald Eagles (Haliaeetus leucocephalus).

Abstract

Birds of prey are renowned for their excellent visual acuity, but they are often not given visual access consistent with their natural behavior when housed under managed care. Often, these birds are housed under managed care after sustaining injuries, which prohibits their return to the wild. In addition, many of these rescued raptors do not have the same history of acclimation to human presence as other zoo animals due to being wild-hatched. These factors lead to a potential welfare concern for raptors under managed care, which may not appropriately address their natural and individual histories. We assessed how the removal of a visual barrier (two large doors) may have affected behavior and space use of two bald eagles (Haliaeetus leucocephalus) housed at Zoo Miami. Before the visual barrier being removed, the eagles could not see people approaching their habitat from one out of two possible sides. We found that for one individual, stress behaviors such as gular fluttering significantly decreased after the removal of the visual barrier, and resting significantly increased. The birds also utilized their habitat more evenly after the visual barrier was removed and were seen at higher, more species-typical altitudes within the habitat. These findings suggest that increased environmental visual access for zoo-housed raptors may be a simple way to improve their overall welfare.