Imagine an animal so perfectly adapted to its world that when the rules changed, the very traits that kept it alive started getting it killed. Meet the kakapo, a giant, nocturnal, flightless parrot from New Zealand that became the subject of one of the most extreme, sci-fi-level conservation rescues in history.

This episode explores how millions of years of predator-free evolution left the kakapo defenseless against introduced mammals, and how a handful of survivors have been pulled back from the brink through GPS backpacks, diet manipulation, full genome sequencing, and round-the-clock human intervention.

• Island syndrome and why this six-pound parrot traded flight for a soft-feathered, ground-dwelling life
• The bizarre lek breeding system, with males booming for up to eight hours a night for four months, tied to rimu tree ...