Deciding which species are appropriate for zoo housing involves ethical trade-offs between welfare, conservation value, education, and biological suitability.
The ethics of zoo species selection is among the most contested questions in zoo biology and animal ethics. Traditional zoos have historically selected species based on public appeal rather than welfare suitability, resulting in collections including animals that cannot thrive in captivity. Modern zoo philosophy increasingly applies welfare-based species suitability criteria, but financial pressures often sustain the keeping of problematic species. The case of elephants in zoos illustrates the tension most sharply: they generate significant visitor interest but face documented welfare compromise in most captive settings. Progressive zoos are phasing out elephants while others continue to acquire them, highlighting the absence of binding welfare-based standards for species selection.