Here we use a citizen science based dataset on human-derived visual aesthetic attraction scores for nearly all the bird species of the world13 to determine how certain colors and morphology related traits affect human aesthetic preferences for bird species. The largest advance that this study provides to the current knowledge is the scale of the investigation, which covers nearly all bird species of the world, combined with the high resolution, as we use a direct measure (user derived through a web application) of bird aesthetic attractiveness to people. The latter represents a large improvement, as so far studies at such a large taxonomic scale could only use indirect proxies for human preference, such as number of likes for a specific species in Instagram14, or the occurrence of the species in social platforms15.