On the first of September, the kākāpō — the world's heaviest parrot, flightless and found nowhere else on Earth — crossed a threshold unseen in three-quarters of a century, its population reaching 325 birds after 90 chicks were added in a single breeding season. The recovery, which began in 1995 with just 51 survivors of a near-extinction wrought by introduced predators, has long measured its progress in decades rather than seasons. This year, a rare and abundant fruiting of the native rimu tree unlocked the birds' ancient reproductive instinct, reminding us that nature's recoveries often hing