Kevin Omland is an evolutionary biologist at the University of Maryland at Baltimore County, and he knows as much about mallard-duck coloring patterns as anyone; it was his graduate thesis. “I looked at male mallards and thought, gosh, they exhibit so many wonderful colors, I wonder which ones females care about,” he says. Do lady ducks lust after the males’ green head plumage? Or maybe it’s the blue patches on the males’ wings? Then again, what female duck can resist a nicely proportioned set of white “neck tie” feathers? After four years of documenting mallard courtships, Omland found that none of those mattered. All they cared about was the brightness of the guy’s yellow-orange bill.
