The wild herd of Kaimanawa horses have been injected with a contraceptive to help control numbers.
The animals are mustered in the central North Island almost every year, but this new injection could change all that.
Just three weeks ago the horses were living wild in the Kaimanawa Range. But now they're being trained and domesticated.
"They're really cool little ponies, they are completely different to run of the mill domestic horses," Kaimanawa horse trainer Kate Munn said.
To protect the environment, the wild herd is capped at about 300, so almost every year since 1993 hundreds of horses are rounded up and rehomed.
"They'll hopefully become kids' ponies," Munn said.
The uncertainty during the pandemic has meant people are more hesitant than ever to take on a Kaimanawa horse - 150 homes were needed this year, but only 88 were found.
"Mustering to rehome is unsustainable, it's very difficult to find qualified homes with the right facilities," Kaimanawa Heritage Horses Welfare Trust member Sue Millard said.
Which is why a new equine contraceptive injection has just been approved. It's a project Millard has been working on since 2009.
"It's a great first step on the ladder and we're hoping it proves to be immensely successful," Millard said.
Sixty of the mares in one herd have been injected with birth control that lasts four years.
It reduces the breeding rate, and the need to find homes for hundreds of wild horses.
"In eight years' time, we would be looking at musters every two to four years," Millard said.
"From a selfish point of view, I was like 'oh bummer we won't get to work with them as much', but actually the horses come first and not having as many numbers is a good thing for them," Munn said.
And it's a good thing for the environment.
