There's probably some information on the shape of the uterus, which can relate to things like litter size, and maybe for a few other features besides, but it tends to be rather less than you'll find for the males. But you won't typically find, in most descriptions, is quite so much information on the female reproductive tract. So male reproductive anatomy can tell us quite a bit. Alternatively, if your species is monogamous then neither of these things are much of a concern. So, in those species, the males tend to be smaller, but their testicles larger (proportionately speaking). Instead, what you really need is to produce so much sperm that yours swamps that of your rivals. But if the females are sexually promiscuous, that's pointless. In order to gather a harem of receptive females around itself, a male has not only attract them to itself with suitably impressive antlers (or whatever) it also has to fight off rivals, and it's going to have to be big and muscular to do that. This is because the rule is not simply 'the bigger the animal, the bigger its gonads'. Testicular size, for example, can tell us about its mating strategies. Obviously, reproductive anatomy is an important field if we want to really understand how an animal functions and behaves. And there's a high probability that there will be quite a lot of information about the shape of its penis and the size of its testicles. There will also be discussions of the shape and proportion of the limbs and the exact colour of the fur, as well as any horns or antlers it might have. If you look at any really detailed description of the physical appearance of a mammal species, you will find a lot of intricate information on the shape of the teeth (especially the molars and premolars) and the dimensions of the skull.

Dolphin vagina