alright, considering i know nothing about these animals or biology i am gonna call that a win

Only thing I can think of off the top of my head is that the temperature is linked to food availability, when food is available its fine to make a bunch of females since their off spring wont have to compete for food, but if food is scarce then its better to make males, the ones best suited for survival will end up getting to mate, so its as if nature is using the food scarcity as a filter to get rid of bad genes