CAT 2026 Slot 2 VARC Q18: Evidence based

Landing in New Zealand, the Dutch colonists weren't much impressed with the small-bodied, slender-snooted flightless birds called kiwis. "Their beak, which is much too long, gives them an air exceedingly stupid," one naturalist noted in 1810. They nicknamed one type the "bush goblin" because of its brown, hair-like feathers.

Silly-looking or not, though, the bush goblin—the smallest kiwi, more commonly known today as the little spotted kiwi—exhibited a genius for survival in the harsh alpine forests, where its ancestors had persisted for some 26 million years. Adults used burrows to shelter their young and dug shallow, camouflaged nests. These sheltered sites helped them cope with difficult conditions.

Still, these adaptations did not prepare the little spotted kiwi for the colonial-era transformation of its ecosystem, particularly the onslaught of imported European animals, from deer and possums that damaged delicate forest vegetation to ravenous stoats that soon developed a taste for kiwis. Several of the dozen-odd kiwi species went extinct, and by the 1950s the little spotted kiwi, whose original range stretched across much of the islands, persisted only on one predator-free island in Cook Strait, off New Zealand's southern coast.

"Our isolated fauna had simply not been exposed to these predators," says Dr. Alistair Vance, an ecologist with the Wild Kiwi conservation program.

Now Wild Kiwi is using descendants of those few thousand island survivors, called Cook Strait kiwis, in a new effort to seed a mainland kiwi revival. They've imported 30 kiwis to a preserve on the edge of the Southern Alps, in the remote interior of South Island. This sanctuary is a challenging place, desolate much of the year, with one of the world's most mercurial weather patterns—relentless snowstorms followed by sudden thaws.

The imported kiwis occupy two fenced "exclosures," cleared of invasive possums (courtesy of Vance's terrier) and of feral stoats (which slunk off once the possums disappeared). A third fenced area contains the program's Wild Training Zone, where two other rare birds (takahes, a larger type of flightless bird, and keas, a somewhat fearsome parrot known for ripping apart car parts) currently share terrain with controlled numbers of stoats, learning to evade them. It's unclear whether the Cook Strait kiwis, which are perhaps even more predator-naive than their now-extinct mainland kin, will be able to make that kind of breakthrough.

For now, though, a recent warm spell has led to a kiwi chick boom, raising the Wild Kiwi population to about 150, with other sanctuaries adding to that number. There are also signs of rebirth in the landscape itself. With their constant digging, the kiwis trap moisture and allow for seed germination so the deer-damaged forest can restore itself.

They have a new nickname—a flattering one, this time. "We call them forest gardeners," Vance says.