But then, neither can you. Instead of just one mating strategy, these lizards have three distinct types of behavior that constantly compete with each other in a perpetual cycle of dominance. Dominant, orange-throated males establish large territories within which live several females. The orange males can't successfully defend all their females against these disguised interlopers, who cluster on the fringes of the territories held by the orange lizards. However, a large population of sneakers, which have no territory of their own to defend, can be overrun by blue-throated males, who defend territories large enough to hold just one female.
Sneakers have no chance against a vigilant, blue-throated guard.
But once the sneakers become rare, powerful orange males flourish, grabbing territory and females from the blue lizards. Now, the blue males lose out. The orange strategy defeats the blue strategy to complete the cycle. Reporting in a recent issue of Nature , biologists Barry Sinervo and Curt M. Lively of Indiana University discuss field data showing that the populations of each of these three types, or morphs, of male lizard oscillate over a 6-year period. They found that when a morph population hits a low, that particular type of lizard produces the most offspring in the following year, helping to perpetuate the cycle.