This book challenges the assumption that humans generally treat all animal species equally according to their need of conservation. Recent studies suggest that humans show strong preferences toward particular animal species/taxa and are willing to protect them more than others. Such understanding of human preferences is an important part of conservation strategies. Special attention has to be paid to less preferred, but endangered species. Fortunately, the highly preferred species are present in almost every family and also among threatened species. Thus, the zoos can replace preferred but common species by endangered one that meets both, conservation as well as visitor's aesthetic criteria.