High rainfall and relatively warm weather makes for dense forestation right across the island. Native plants include the world's southernmost podocarps (southern conifers) and hardwoods such as rata and kamahi in the lowland. A great network of trails makes for fabulous bush walking in pretty much all weather.
There are many species of birds on Stewart Island that thrive because of the absence of cats, rats, stoats, ferrets, weasels and other predators that man has brought to the main islands. Concerted conservation efforts by the Islanders and New Zealand’s Department of Conservation keep predator numbers down and support threatened species.
The birds of Stewart Island include weka, kaka, albatross, the flightless Stewart Island kiwi, silvereyes, fantails, and kereru (wood pigeon). The endangered Yellow-eyed penguin has a significant number of breeding sites here and there are large colonies of Sooty Shearwaters on the offshore Muttonbird Islands.