Drab male guppies have hit upon a mating strategy that could be easily adapted to the bar scene: Home in on the female besieged by ugly males. In lab-raised descendents of wild guppies (Poecilia reticulata) females prefer mates with large orange body spots (image). But a new study suggests that less-colorful male guppies (inset) aren't totally at the mercy of picky females. In lab tests where researchers placed a female guppy and two colorful males in compartments at one end of an aquarium and a female and two lackluster males at the other end, a male released in the center of the tank more often gravitated toward the end with the less colorful competitors, especially if the test male had less than 9% of its body covered by orange spots and had a history of rejection by females, the researchers report online today in the Proceedings of the Royal Society B. A previous lack of success in mating presumably makes a male recognize his own plainness, which in turn leads him to choose courtship situations where his chances of success will be greater, the researchers suggest. The tactic also explains why drab males persist in guppy populations: By choosing to woo females surrounded by unexciting suitors, even a homely guppy scores every once in a while.
See more ScienceShots.