Its a really tricky one, and one that (obviously) my character has a strong interest in. The simple answer is simply “We don’t know”
However we can speculate.
Dragonhawks are an interesting one. I imagine they would live a fairly long time. They are classified as Draconic, not just reptiles, they are (And blimey I hate using this as a signifier of intelligence given my personal views on the subject) Intelligent enough to have a concept of internal racism. That requires cognitive thought, even if misguided cognitive thought. Before anyone says ‘Err Brigante ever seen red ants and black ants fight?’ That is pheromone based instinct and hive behaviour. Ants may have the largest brains in comparison to their size of any creature on earth, but they are not fighting out of racism, just instinct.
Dragonhawks are able to discriminate between the different breeds, and they will dislike some breeds, but be fine with other breeds. That’s selection, that implies a mind and motive behind it.
So they’re smart, a trait of Dragons, They’re Draconic, err, by definition a trait of Dragons, heck, they even have the breathing fire bit nailed. Dragons live for ages, in both ancient and modern myth, and in Azeroth, I don’t think they would live as long as an Elf, but I can’t see 1,000 or so years being out of the question.
Hippogryphs again are something special, They’re not ‘just’ a beast, or ‘just’ a mount. There has to be something about them, that appealed to the Kaldorei way back in the day, as after all, Wyverns were a ‘thing’ and the Kaldorei made no efforts there.
It is human, well, lets say, ‘Bipedal and Sapient’ nature to like things that you like, to stick around for a while. I mean if you consider the cost of keeping a pet mouse, as opposed to a pet Dog, and how high Maintenance Dogs are, then why the heck are Dogs such a popular pet as opposed to mice? (Nothing against mice…Jaysis even as I type that I’m like 'As if a Mouse is going to be reading the WoW forums, sees my post and flags it as racism!
)
We like dogs more for several reasons, but one of them is, that all things going well, a Dog is going to be with us for ten or more years, as opposed to the House Mouse which is lucky to make one year.
Why ‘Waste’ your time in an emotional attachment to something that is going to be dead next Wednesday, in terms of your lifespan?
I think that’s why the Elven races choose the mounts they do. Life Expectancy being a large factor. As such I can see Hippogryphs being capable of reaching fairly venerable ages, certainly much older than a human.
Wyverns… Sighs and gets his pedant rant out of the way first Which are not even damned Wyverns, if you want a Wyvern from mythology then you take a damned Dragonhawk and give it two back legs, -That- is a Wyvern, What you, Blizzard are calling a Wyvern is a Winged Manticore, two totally different mythological creatures with different cultural origins!
Ahem. Calms…
‘Wyverns’ are a really tricky one, even trickier than the others, for one primary reason (and I hate that Blizzard put this in, because it makes no damned sense). Apparently they can talk. I know. I know, that makes no sense. Not a jot of sense. Why didn’t the Kaldorei reach out to them in the first Legion Wars. You’ve got another Sapient Race who can talk and fly and don’t you think they would be good people to get on side to save your mutual home? I don’t think Blizzard thought that one through, it suddenly makes the Horde an absolutely hideous thing “I used to be a poet you know? I would tell tragic romances that would have people weeping in despair and ecstatic joy…Then the Horde got me ferrying lazy murderhobos around Stonetalon mountains… How the mighty have fallen” Adventurer: “Shut up, I don’t need a sob story from a glorified teleportation device!”
Age has to have been a factor as to why Kaldorei and ‘wyvern’ never made contact or common cause before. As such I’d reckon that 'Wyvern’s (No I’m not going to let that go) have a lifespan more in line with an Orcish or Human one. Lucky to hit 100. Also, fun fact, ‘Wyverns’ are definitely Mammalian in nature, but they lay eggs. Know what that makes them?
Monotremes. So they are in such good company as the Duck Billed Platypus, and the Echidna, which are the only two mammalian species to lay eggs.
Who knew…
Gryphons…I’m gonna go with my ‘Wyvern’ theory. They’re associated with humans, and with Dwarves, Humans live 100 years absolute tops, Dwarves about 300 (I believe) It makes sense for a Gryphon to live as long, to be desirable as a mount to both species, You’ve got to be looking at, well at least a human lifespan.
Crawgs? I have no idea, all I’ve got there is “Have you looked at a Crawg?”
If I were a Crawg, I’d want my life expectancy to be as short as possible…