25-12-2008
It does indeed seem young for a large parrot and I would also have been more inclined to think that 40 or 60 would be a good age for them to reach. However, Juniper and Parr ("Parrots", 1998) say "The kaka's lifespan is thought to be about 20 years". Heather and Robertson ("Field Guide to the Birds of New Zealand", 2000) say "The oldest Kaka in the wild was still breeding at 14 years old, but in captivity they have lived to over 20 years." Moynihan (in Robertson, "Complete Guide to New Zealand Birds", 1985) says "Kakas could be long-lived - one bird in captivity lived for at least 20 years...". Forshaw and Cooper ("Parrots of the World") don't mention lifespan at all.
As for their close relative the kea, Heather and Robertson (2000) say "The oldest Kea recorded in the wild lived over 20 years" and Temple ("The Book of the Kea", 1996) says "While pampered birds in aviaries may reach 30 or 40 years, only a small percentage in the wild would reach 15, the oldest verified age of a free-flying bird."
So it would seem that for both kea and kaka, twenty years is actually a good old age for them (although in captivity they may add on another ten years or so). It is quite unusual in as much as NZ birds in general are slow-breeding long-lived species, so one would have suspected these large parrots to follow this rule.
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