Conservation prioritization is dominated by the threat status of candidate species. However, species differ markedly in the shared genetic information they embody, and this information is not taken into account if species are prioritized by threat status alone. We developed a system of prioritization that incorporates both threat status and genetic information and applied it to 9546 species of birds worldwide. We devised a simple measure of a species' genetic value that takes into account the shape of the entire taxonomic tree of birds. This measure approximates the evolutionary history that each species embodies and sums to the phylogenetic diversity of the entire taxonomic tree. We then combined this genetic value with each species' probability of extinction to create a species-specific measure of expected loss of genetic information. The application of our methods to the world's avifauna showed that ranking species by expected loss of genetic information may help preserve bird evolutionary history by upgrading those threatened species with fewer close relatives. We recommend developing a mechanism to incorporate a species' genetic value into the prioritization framework.