[xzins]

Let's see.

This chick menstruates more so she can have sex more, so she can get pregnant more, so she can eat meat more, because she menstruates more.

Strikes me as stark circularity.

[f.Christian]

How different is this than reading chicken entrails ... tea leaves --- crystal balls --- hand palms -- mind reading ?

[ElectricRook]

This chick menstruates more so she can have sex more, so she can get pregnant more, so she can eat meat more, because she menstruates more.

Perhaps one female is able to become fertile more than once a year. But she can only make more babies if she eats a better diet. So she choses the most sucessful male hunter, who brings her the higher quality diet. She keeps his attention with sex. The regular sex fills his desire to advance his genetic lineage. She and the children eat a better diet than their peers. And these children are more likely to survive, with the genes for more fertility, and better hunter.