Lady Lizard Found to Lord It Over Males

In the eternal war between the sexes, the lady side-blotched lizard wins it all: She selects her many mates, decides where they’ll live and even determines if they will have sons or daughters. Virtually every element of the mating and reproductive cycle of the small American lizard is controlled by choices made by the female, according to UCLA biologist Ryan Calsbeek.

“This is the ultimate example of a female having her cake and eating it too,” Calsbeek reported in the Proceedings of the National Academy of Sciences. “It would be like a human female who marries a short, dumpy rich guy and then has an affair with a muscular 20-year-old to have a handsome son who grows up in a mansion and goes to the best schools.”

The side-blotched lizard is the most common lizard in the American West. It lives among rocks west of the Rocky Mountains from Canada to the Baja Peninsula in Mexico. The animal is small -- with the male reaching about 2.3 inches and the female about half that -- but it has a complex mating and reproductive system, Calsbeek said.

Generally, the female picks the mate she’ll live with. Calsbeek said he and his co-author observed that the female generally prefers a big male who lives on a big rock in the best location.

To see whether the female was selecting the choice living site or the choice male, the researchers moved the rocks around, putting the big males on poor rocks and the little males on the best rocks in the finest neighborhoods. The female lizards seemed to prize comfort over all else, choosing small males with the fancy rocks as the first mate and live-in partner.