Humans play a role in deciding which species are preserved and which will perish in the current extinction wave. Because of the Similarity Principle, physical attractiveness and likeability, it is argued that public choice would greatly favour the survival of higher-order species at the expense of others. This paper empirically tests this argument by considering a hypothetical ‘Ark’ situation. Results are drawn from surveys of 204 members of the Australian public who were asked whether they are in favour of the survival of each of 24 native mammal, bird and reptile species. The species were ranked by percentage of ‘yes’ votes received. Species composition in various fractions of the ranking was determined. If the Similarity Principle holds, mammals would rank highly and dominate the top fractions of animals in the hierarchical list that would be saved (i.e., taken on the ‘Ark’). We find that although mammals would be over-represented in the ‘Ark’, birds and reptiles would also be well represented when social choice is based on numbers ‘voting’ for the survival of each species. Differences in public support for species in the relevant taxa are not as statistically significant as one might expect from the Similarity Principle.