Threespine sticklebacks hatch in fresh water pools near streams. When they mature, they need to make their way back to the ocean to live. So if their way to the ocean is cut off, they’re screwed. Or are they?
This is the stickleback. The males of the species have a reputation for being wonderful fathers. They are so baby-crazy that if their nests are empty they will steal the eggs of other males, just to get a little something to watch over. But, wait! Just how did their nests become empty in the first place?
Supernormal stimuli make birds ignore their eggs (and then their chicks), cause fish to fight dummies (while live competitors go uncontested), and can drive humans back to sugary snacks. Find out how these special stimuli use just the right trigger to make an animal destroy itself.
Lake Washington, the largest lake in the Seattle area, has long been home to a soft-skinned fish called the threespine stickleback. But over the past fifty years, the lake's population of sticklebacks has changed dramatically: today, most of the fish sport partial or full body armor, a throwback to their origins as…