Standards and policies intended to safeguard nonhuman animal welfare, whether in zoos, farms, or laboratories, have tended to emphasize features of the physical environment. However, research has now made it clear that very different welfare outcomes are commonly seen in facilities using similar environments or conforming to the same animal welfare requirements. This wide variation is almost certainly due, at least in part, to the important effects of the actions of animal care staff on animal welfare. Drawing mostly on the farm animal literature, we propose that this “human dimension” of animal welfare involves seven components: (1) positive human–animal interaction, (2) consistency and familiarity of keepers, (3) treating animals as individuals and taking account of their personalities, (4) the attitudes and personalities of keepers, (5) the keepers’ knowledge and experience, (6) the keepers’ own well-being, and (7) the influence of facility design on how keepers and others interact with the animals. We suggest that attention to these human factors provides major scope for improving the welfare of animals in zoos.

旨在保护非人类动物福利的标准和政策，无论是在动物园，农场还是实验室中，都倾向于强调自然环境的特征。但是，现在的研究表明，在使用类似环境或符合相同动物福利要求的设施中，通常会看到非常不同的福利结果。这种广泛的差异几乎可以肯定至少部分是由于动物护理人员的行动对动物福利的重要影响。我们主要借鉴农场动物文献，我们认为动物福利的这种“人的维度”涉及七个组成部分：（1）人与动物之间的积极互动；（2）饲养者的一致性和熟悉度；（3）将动物视为个体并采取他们的性格，（4）饲养员的态度和性格，（5）饲养员的知识和经验，（6）饲养员自身的福祉，以及（7）设施设计对饲养员和其他人与动物互动的影响。我们建议注意这些人为因素可为改善动物园动物的福利提供主要范围。