New Zealand is a nation that takes its birds seriously, and it’s got very special ones. The country’s currency is adorned with images of winged species found nowhere else, including the yellow-eyed penguin and the black-masked kokako. The logo of the national air force is stamped with the famed kiwi — a chicken-sized puff of feathers that cannot fly.

But many of those birds and other native wildlife are under assault from species that showed up with settlers to the island nation 200 years ago. And on Monday, Prime Minister John Key announced that, generations after they came, the invaders would have to go.

New Zealand, he said, has adopted the “ambitious goal” of eradicating its soil of rats, possums, stoats and all other invasive mammals by 2050. The name of the plan: Predator Free New Zealand.

“This is the most ambitious conservation project attempted anywhere in the world, but we believe if we all work together as a country we can achieve it,” Key said in a statement, adding that invasive predators have surpassed poaching and deforestation as the biggest threat to New Zealand’s wildlife. Key held a tuatara, a lizardlike native reptile, after announcing the plan, the Financial Times reported.

This isn’t the first time New Zealanders have contemplated the idea of a full wipeout of introduced predators, which the government says kill 25 million native birds a year and spread diseases to cattle and deer. In 2012, it was championed by the late scientist Paul Callaghan, who said the concept could be New Zealand’s equivalent of the Apollo space program. But the idea was mostly viewed as fanciful.

New Zealand already spends about $40 million a year on invasive species eradication programs, and it’s cleared more than one-third of its 220 islands of predators. But Key suggested Monday that the traps, airdropped poison and fencing already in use haven’t been cutting it. He said $2.3 billion had been devoted to the new plan, some of which would go to a new public-private partnership that would come up with new technologies to defeat the enemies.

“For the first time, technology is starting to make feasible what previously seemed like an unattainable dream,” Science and Innovation Minister Steven Joyce said in a statement.

The funding might not be enough, however. A government research arm previously said the effort would take $20 billion, The Post’s Karla Adam reported.

Holly Jones, an assistant professor of conservation biology at Northern Illinois University who studies mammal eradication on New Zealand’s islands, said the biggest island ever cleared of rats is South Georgia Island, a British territory in the Southern Atlantic. New Zealand’s North Island is 29 times larger, she said — and its South Island is 39 times larger.

“What they’re proposing would be incredible if they could pull it off, because their fauna is so vulnerable,” Jones said. “My first thought is that if anyone can do it, the Kiwis can. They’re the ones who have really pioneered the technology to eradicate mammals. But it’s going to be a big task.”

The greatest obstacle might be convincing the public. This kind of eradication is usually carried out by spreading poisoned bait, Jones said, something “some people just don’t like the idea of.”

Conspicuously missing from the government’s announcement were the invasive mammals whose fates have been at the center of most conservation debates in New Zealand: cats.

For as much as they love their birds, New Zealanders also are quite fond of cats. According to some estimates, the nation has more cat owners per capita than any other. The country’s conservation minister has proposed a household cat limit. In 2013, environmental activist Gareth Morgan suggested hunting down and killing every feral cat in New Zealand (a proposal that, Morgan told The Washington Post, elicited lots of hate mail from Americans.)

“Cats are the major sticking point to a pest-free New Zealand,” James Russell, an ecologist at the University of Auckland, told The Post.

But cats also have a well-placed champion — none other than Prime Minister Key himself.

Key is the owner of a cat named Moonbeam Smokey Fluffy Key, a grayish feline whose “unconditional” love he has praised in Parliament.

And so it was little surprising that Key, when asked by reporters about cats’ place in the Predator Free plan, said house cats — emphasis on house — would be spared. Roaming cats, on the other hand, are on the hit list.

“If you’re asking about Moonbeam, Moonbeam is safe,” Key said. “If you’re asking about feral cats … then their time is limited.”

“In terms of the domestic moggy,” he added, using a Britishism for house cat, “they have plenty of years in front of the fire at home.”