How hard can it be to spy on turtles? Most striking about map turtles is the huge difference in size between males and females. The male is the smaller one. The whole assembly was dropped at bottom of the lake early in the morning and recovered at the end of the day. If a typical male encounters many females of varying sizes, which happens because of the unusual overwintering habits of this species, and cannot possibly mate with all of them, he should prefer to mate with the larger ones. Our prediction was straightforward.