The five ‘lost’ birds found singing in Arthur’s Pass

Hamish Reid was walking back down the Poulter Valley around dusk when he heard five mohua singing in the trees beside the track. He noted the sighting, sent the details to DOC and carried on, apparently unaware that he had just delivered the sort of message capable of making a conservation ranger jump up and down.

The excitement makes more sense with a little history. Mohua, also known as yellowheads, were virtually wiped out in North Canterbury during the 1990s, and had not lived in the Poulter Valley for around 20 years when 41 birds were released there in 2022. DOC hoped the new population would settle, breed and slowly reclaim the valley, but follow-up monitoring found very little. As far as anyone could tell, the birds had gone.

Then Hamish heard five of them behaving as though nobody had been looking. They could be survivors from the original release, which would mean the population has been keeping an exceptionally low profile, or they could belong to a previously unknown remnant group. DOC says the second possibility could make the birds genetically distinct, although there is also something deeply satisfying about the idea that five small birds simply avoided a government department for four years.

Mohua are hard to ignore once you actually see one. They have a bright yellow head and breast, a dark eye and the slightly over-alert expression of a bird that has survived several poor decisions made on its behalf. Their decline was driven largely by introduced predators, which is why the work happening around the Poulter and neighbouring Hawdon valleys has involved years of aerial predator control and volunteer trapping.

That work rarely produces a neat before-and-after moment. Forests recover unevenly, bird populations move, monitoring trips miss things and volunteers can spend days checking traps without receiving any obvious confirmation that the place is getting better. The reward is often delayed or hidden somewhere higher in the canopy, which makes the discovery of five mohua feel less like a lucky sighting and more like a small receipt for years of work.

Hamish knows the valley well. A retired Canterbury vet, he volunteers his time trapping rats, stoats and weasels, carrying gear into the bush and doing the kind of repetitive work that rarely makes it into the public version of conservation. He says the change in the valley can now be heard, with kiwi and ruru calling again and other native birds returning as predator numbers fall.

He described the sound as an orchestra, which might feel slightly romantic if he were not one of the people carrying traps into the valley and doing the unglamorous work behind the music. The forest does sound different when more of its birds are alive, and that is probably a better measure of recovery than any glossy campaign could offer.

The five mohua are not proof that everything is fixed, because conservation almost never offers proof that tidy. They are a sign that the years of work may be holding, and that a population everyone feared had vanished might have been living just beyond the reach of the last monitoring trip.

Hamish hopes the birds decide to remain in the Poulter and build a larger population there. For now, they are still somewhere in the valley, singing loudly enough at dusk for the right person to hear them.