ABSTRACT

Enrichment is presented to improve the welfare of captive animals but sound is frequently presented with the assumption that it is enriching without assessing individuals’ preferences. Typically, presented sounds are unnatural and animals are unable to choose which sounds they can listen to or escape them. We examined preferences of three zoo-housed gorillas for six categories of sound. The gorillas selected unique icons on a computer touchscreen that initiated brief samples of silence, white noise, nature, animal, percussion, and electronic instrumental sounds. Following training, gorillas selected each sound paired with silence (Phase 2), each sound paired with each other sound (Phase 3), and one sound among all other sound categories (Phase 4). Initially, a single sound was associated with each icon, but additional exemplars of the category were added in phases 5–8. Preferences were generally stable and one gorilla showed a strong preference for silence. Although there were individual differences, a surprising general preference for unnatural over natural sounds was revealed. These results indicate the importance of assessing preferences for individuals before introducing auditory stimulation in captive habitats.

摘要

丰富化的目的是改善圈养动物的福利，但声音常常假设它是丰富化的，而没有评估个体的偏好。通常，呈现的声音是不自然的，动物无法选择他们可以听到或逃避的声音。我们研究了三只动物园饲养的大猩猩对六类声音的偏好。大猩猩在计算机触摸屏上选择了独特的图标，启动了沉默、白噪音、自然、动物、打击乐和电子乐器声音的简短样本。训练结束后，大猩猩选择每种声音与静音配对（第 2 阶段）、每种声音与其他声音配对（第 3 阶段）以及所有其他声音类别中的一种声音（第 4 阶段）。最初，每个图标都有一个声音，但在第 5-8 阶段添加了该类别的其他示例。偏好总体稳定，一只大猩猩表现出对沉默的强烈偏好。尽管存在个体差异，但令人惊讶的是，人们对非自然声音的普遍偏好超过了自然声音。这些结果表明在圈养栖息地引入听觉刺激之前评估个体偏好的重要性。