This Graphium policenes is one of nearly 40 species of swordtail butterflies known to inhabit Africa. Photograph by Rebecca Hale, NGM staff Farmer Philippe Andé finds solace in the creatures.
Ryan and graduate student Molly Cummings have studied a Mexican swordtail fish, Xiphophorus multilineatus, and found that females prefer males with shiny tails. "We haven't figured out what that ...