I think most elders would be over 700 years old, in some cases it is assumed that they can live well over a millenium. Even a very young predator by their ageing brackets, would probably be older than an elderly man by our terms. Even the unbloods from AVP were probably 150 years old or more. A good comparison would be to say that times a humans life span by 10 or so, & u've got a rough estimate for a predator lifespan. Eg. a 150 year old predator, would in their terms, equal a 15 year old teenager in our terms. Although, since elders reportedly can live for over a milleium, that would make them a 100 year old man by our terms, meaning that they would be incapable of really fighting very well anymore, having passed their prime, although it seems to be completely different than that, as the elders we have seen so far don't exactly look old & feeble, they look menacing & powerful, as if they would decimate all before them with ease, even the mightiest of the younger challengers, so that analogy might not be entirely accurate.