The pekapeka long-tailed bat saw off a number of its winged rivals to win the competition, which aims to raise awareness of the threats faced by local wildlife.
Perhaps unsurprisingly this was the first time a bat has been included in the Bird of the Year running, but its inclusion this year is not without reason.
The long-tailed bat is threatened by habitat loss, predators and climate change, just as many birds are.
It uses echolocation to hunt moths and mosquitos, has a wingspan the size of a human hand and weighs about as much as a coin.
The Bird of the Year website, run by New Zealand independent conservation organisation Forest & Bird, lists the bat as "in serious trouble".
"A huge congratulations to the pekapeka long-tailed bat for winning £BirdoftheYear 2021!" Forest & Bird tweeted.
"Despite being our only endemic land mammal, most people don't even know they exist, which makes their win even more outstanding."
The competition was won in 2020 by the kakapo, a nocturnal flightless parrot - this year, the long-tailed bat was chosen after more than 50,000 votes were registered from 100 countries.