Relations with males are a crucial part of the story.
"I'm used to fighting and arguing with males," she said.
Put simply, females prefer to mate with males that have more elaborate songs.
Female prairie voles injected with a substance that blocked oxytocin failed to bond with males in the usual way after mating, while females injected with oxytocin developed bonds with males willy-nilly.
DNA studies also show that females mate only with males outside their pods, revealing another potential problem.
"They are showing subterfuge and mating with males in secret to their own best advantage," he said.
So the females may have had to mate with males in the chimpanzee lineage in order to produce viable descendants.
Occasionally they mate with males and produce fertile eggs but then return to their original same-sex partners.
Females had access to regular sex with males, and orgasm as an ovulatory mechanism was no longer so useful.
Greyhound races are not segregated, presumably signifying that Greyhound owners and trainers believe that females can compete successfully with males".
While far more often associated with males than females, these features may also occur in both as well.
