All current mega beasts are of animal intelligence, and so, presumably, breed the same way as animals, i.e. viable male impregnates viable female when opportunity arises. It's worked with the few cases I've had opportunity to try with captured pairs.
Intelligent semi mega beasts presumably use the same breeding model as other "wild" intelligent creatures (such as troglodytes), i.e. the animal breeding model. This can be seen when a group camps in a cavern. I don't know if anyone has tried to set up any breeding programs for intelligent semi mega beasts, though, but it has probably been done.
I figured as that is what my observations seemed to suggest but didn't want to presume, it is disappointing that they truly are nothing more then big animals, but not unexpected, most fantasy settings I know treat at least dragons as intelligent if not giants and ettins.

Fully intelligent megabeasts or otherwise for 44.12 rely on marriage rules and it happens offscreen in w.g, only slow learners like 'Giants' rely on animal-level mating given the practices you can partake in to breed troglodytes and trolls by breeding them on a chain or in cages near compatible mates. Though its fully possible now on 47.01 that cyclopian family groups could be introduced to one another in fortress mode through controlled introduction to one another on a chain in the hopes of them becoming lovers, though its not much of a existance.
This answers my question, the intelligent ones do get treated like Civilised races its just hidden, this changes the question to why isn't this shown in legends in the same manner as civilised races?

The purposes for breeding cyclopses would be a difficult lengthy process, that isn't nearly as productive as breeding trolls (putting in pits, slow down siegers, long lifespan for cage exhibits) for albiet a cyclops has much more potential (once a few years has elapsed) to be used as defensive failguard or guardian of a pit. Taking into account megabeast caps too.
- The civilized concept of marriage not being applicable to megabeasts and uncivilized creatures and thinking about life-bond/relationship status of a mate -monogomy is a nice thought but probably warrants a suggestion thread instead
Its wasn't really a suggestion in my mind, you've got more of a suggestion then I do as I have no interest in capturing or breeding Mega or Semi-Mega Beasts, I personally prefer adventure mode, I'm really looking forward to a more complete adventure mode as I would prefer to play fortress mode in adventure mode with my character as the expedition leader/overseer and the other six of the starting seven can just be my party members, just requires the rest of the skills to be made functional in adventure mode.

But I digress so back to the subject at hand, I just thought about how there are no details about them breeding only that they do and I wondered the hows and whys of it being like that, I mean they can breed and the semi-megas can talk and many animals can form family groups or life long pair bonds even tho they are "just" animals so it makes a kind of logical sense for the Historical figure Mega and Semi-Mega Beasts to have them, or at least be more detail then as just big hist fig animals, If a magpie can hold a grudge why not a Roc? if Elephants can grieve their dead family/herd members why not Giants?

I thought my question was less of a "I think you should add this" and more of a "I wonder why you didn't add this?" it is why my question was worded as "would it make sense" and if "they(*'re) intended to not have such motivations?", but I can see how its can be taken as a leading question with suggestive undertones

, I'll remove it.

At this rate none of my questions will last the month.
