EDIT: Goss got there first... never mind xD to be honest, the fact that they age at the rate of captive Kelvics means that I can now half the rate at which Kalina's ageing... she'll now appear to be about 6-7 rather than 10 I'm not so worried about having to squeeze in her learning!I'm not arguing that a Kelvic is theoretically better off than their pure animal counterparts. Yes, it's plausible that they might live longer, relatively, due to care and lifestyle in civilisation. I'm basing my information off of a CS intervention I read a while back (just found it again)
here, but it's very possible I misinterpreted. - though like you say, Goss will set us straight!
I agree that if humans are living so long, then Kelvics should, logically, share their "captive" life-span, but humans are also a lot smaller than current humans, so the longevity is maybe more of a Mizahar fantasy thing, rather than accurate historical fact.
But lifestyle isn't going to add on ten years to Kalina's life. In the under-developed world that Mizahar is, compared to what we know as First-World Earth, life isn't all that markedly different in the wild vs civilisation, in comparison to the countless differences that the real world has between techonology in the US compared to, say, rural Tanzania. The medical equipment we have today doesn't exist in this world, so lifespans of "captive" animals might not exist. I mean, it's reasonable to say they won't, I think.
Medicine in this world is pretty impressive, but she's not receiving vaccinations, or cutting-edge surgery, or even meals which are best suited for high nutrient intake. And she's definitely not being dewormed, following all the filthy water she probably drank from in her way to Nyka!
Anyway, my point is that I don't think the technology in Mizahar is advanced enough for Kelvics to have "captive" lifespans. But that's my tuppence, I wait for the definitive words of The Powers That Be