Enclosure Background Preferences Differ between Sexes and Color Morphs in the Gouldian Finch

SIMPLE SUMMARY: Most animals blend well into their natural environment, which protects them from predators. However, in captive environments, animals are often exposed, which can lead to stress. Research suggests that animals are more difficult to detect in complex environments. We tested background preferences in the Gouldian finch, which occurs in two main head color morphs in the wild. Birds were tested in groups of four in either the same head color (black or red) or mixed head color (two black and two red) pairings. One half of the cage had a simple background pattern, the other a complex background pattern. We measured the time spent in front of each background after 10 days in the cage (phase 1), after which backgrounds were swapped (left to right), and assessed preferences again on day 17 (phase 2). Birds preferred the simple background, particularly in phase 1. However, females initially chose the simple background but used both backgrounds in phase 2, whereas changes in males were not significant. Both color morphs preferred the simple background in phase 1, with the black-headed birds moving to the complex background in phase 2. Results indicate that background preferences differ among individuals, which should be considered when designing enclosures. ABSTRACT: Most wild animals camouflage well into their environment, providing protection from predators, whereas captive animals often contrast with their background. This can cause stress for the animal, which may perceive it as being exposed. Theory suggests that prey is more difficult to detect in front of complex backgrounds; hence, animals should prefer complex over simple backgrounds. We tested this in the polymorphic Gouldian finch by providing a complex background pattern in one half of the flight cage and a simple background pattern in the other half for 10 days (phase 1). Patterns were then swapped and presented for another week (phase 2). Groups of four birds consisting of either pure black-headed or red-headed or mixed head color (two black-headed and two red-headed) pairings were tested. Gouldian finches spent significantly more time in front of the simple background in phase 1 but not in phase 2. Specifically, females preferred the simple background in phase 1 significantly more than males. Moreover, red-headed birds consistently perched in front of the simple background, whereas black-headed birds used both backgrounds, particularly in phase 2. Results indicate that background preferences differ between sexes and morphs, which should be considered when designing backgrounds. Moreover, natural habitat preferences need consideration.