This occurs in the spotted hyena (Crocuta crocuta), whose females are more aggressive and dominant than males.
They possess a false penis and scrotum (pseudo penis and pseudo scrotum). However, the truth is that they have an enlarged clitoris shaped like a penis actually, which is erectile and used to urinate. And the vaginal lips are folded in a way that resembles the scrotal sack of males.
The problem is that this structure takes its toll on them when they give birth; sometimes it even leads to the death of the mother and many babies.
There are different hypotheses about the function of these structures
One hypothesis is that it evolved with a selective function, since at the time of mating, the female must voluntarily retract the pseudopenis canal to facilitate copulation. In this way, the female is the last one who makes the decision, as opposed to what happens in other species.
Adaptive function: when mating with several males, it is very likely that the different sperm will come together in the female’s reproductive tract. As this tract is long and convoluted, it would increase the probability that only the best quality sperm would reach the eggs.
Another possible explanation is that it is simply a side effect of the selection of other male traits in females, such as large body or greater aggressiveness.
In hyenas the social system is matriarchal: the male with the highest rank in the male hierarchy is subordinated to the female with the lowest rank.
The clans function through female philopatry, that is, when males reach sexual maturity they leave the clan in search of another.
Kay Holekamp, zoologist from Michigan State University stated:
“There is no other mammal that copulates, urinates and gives birth through the same duct“