Kakapos: Isolation Proves Dangerous On 'Rat Island'

In a new book "Rat Island: Predators in Paradise and the World's Greatest Wildlife Rescue", author William Stolzenburg talks about the damage done to island ecosystems by non-native species like cats, weasels and rats. The implications for the kakapo in New Zealand are well documented, and this North Country Public Radio article talks about that, and also includes an audio interview with the author.

Stolzenburg tells NPR's Renee Montagne that because its only predators were in the sky, the kakapo had no need to fly and, therefore, couldn't.

"It exuded this particular scent also that was supposed to attract other kakapos," he says. "Of course, when the invaders got to New Zealand — when the rats and the cats and the weasels came to New Zealand — this was a bird that was just set up for massacre, and that's exactly what happened."

Stolzenburg explains that in the 1800s, settlers arriving in New Zealand brought sheep and rabbits with them for game. Sheep ate much of the vegetation, and the rabbits, being rabbits, exploded in population. With their huge numbers and voracious appetites, they began eating the sheep's rangeland. So to deal with the rabbit problem, settlers introduced stoats — a member of the weasel clan and a terrific predator. But the stoats quickly found much easier prey than rabbits — kakapos.