More than 50,000 New Zealanders voted in the annual poll carried out by conservation group Forest and Bird, producing a win for the little-known bird, also known as the rockwren.
The endangered piwauwau is found only in the alpine and subalpine zones of the South Island.
Campaigner Stephen Day said the tiny birds were worth the trip to the Southern Alps to see them, as they were "chock full of character".
The rockwren has a dash of yellow feathers on its flank but is a poor flyer, preferring instead to hop about on rocks, trees and snow on its long legs.
Like many of NZs endemic birds, they are threatened by introduced mammals including rats and stoats.
Forest and Bird chief executive Nicola Toki said she saw the piwauwau's win as a "vote for climate action".
"As Aotearoa's only true alpine bird, these tiny wrens are already feeling the impacts of warmer temperatures, which allow predators like rats and stoats to climb higher and invade their mountaintop homes," she said.
The rockwren benefited from preference voting to take the prize after the little penguin received marginally more first choice votes.
Its win ends the controversial reign of 2021 winner, the New Zealand long-tailed bat, which was granted a wildcard entry.
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