Fishiness of Piscine Birds Linked to Absence of Poisonous Fungi but not Pizza

What is a species? That is one of the main questions in evolutionary biology, ecology, and conservation biology. Another question is this one: Can the degree of fish-likeness in birds be linked to the absence of poisonous fungi? Sparked by recent major ornithological advances we set out to assess whether the reason that some birds are more morphologically like fish than others could be explained by the prevalence of fungi of mild to severe toxicity. Whereas birds of several taxonomic orders are partly or predominantly aquatic, few have adapted so strongly to an underwater lifestyle as penguins (Sphenisciformes).