Zardnaar
Legend
I'd have new dragons inspired by native New Zealand fauna, extinct or extant.
No need to stat them up as new dragons though, just reskin an existing dragon. Change the name and describe it as appearing different and it doesn't matter if the numbers are the same as an existing dragon, especially if the PCs never find out!
Instead of Copper Dragons, maybe Zealandia's mountains are inhabited by mischievous, inquisitive and talkative parrot like dragons.
Venture into the moa-inhabited forests and shrub lands and you risk being devoured by terrifying eagle like dragons with the stats of a Chromatic Dragon, maybe with a damage type swap (e.g. a White Dragon that has Poison damage/defenses like a Green Dragon or a Red that spews Acid like a Black).
…and so on.
Was thinking of turning things up to 11. Moas become axebeaks,
Haast eagles become rock.