[00:00.00]Bright-eyed and bushy-tailed,
[00:02.17]the mammals have finally arrived in force.
[00:06.31]Australian possums.
[00:08.50]Imported for their fur two centuries ago,
[00:11.02]they soon reached plague proportions,
[00:14.03]stripping trees of their vegetation.
[00:16.60]A war is being waged against them.
[00:19.19]Traps set and poison scattered.
[00:22.01]And yet they are now far more numerous than the kakapo ever were.
[00:25.64]A staggering 70 million possums overrun New Zealand's forests,
[00:29.81]where a bird failed, a mammal has succeeded.
[00:33.30]But why?
[00:34.39]The possums were unwitting immigrants,
[00:36.40]while the kakapo have lived here for millennia,
[00:38.67]perfectly adapted to this forest.
[00:40.95]It's an irony that is by no means unique to the kakapo and the possum.
[00:44.90]Right across the Pacific, similar scenes have been unfolding.
[00:48.57]Tiny islands off the coast of New Zealand
[00:50.72]are the last refuge for a host of animals
[00:53.52]now vanished from the two main islands.
[00:56.16]This is Stephens Island,
[00:58.33]one square mile of rock protruding from the ocean. （