The female of the species

I don't know whether this is true or not (it's from a novel I'm currently reading):

Spotted hyenas frequently have twins. The cubs are extremely well developed at birth: they have fur and sharp incisor teeth. One cub will almost invariably attack the other, sometimes while still in the amniotic sac. Death is usually the result. The victor is also typically female and, if she is the daughter of a dominant female, will in turn become the dominant female in the pack. It's a matriarchal culture.

Yikes.