About 85 million years ago, New Zealand split away from the supercontinent Gondwana. On board were plants and animals that evolved without predatory land mammals. Most plants and animals have arrived in New Zealand after crossing the ocean. Many developed unusual features as they evolved in relative isolation.
Many species – such as the flightless kiwi and the giant kauri tree – are found nowhere else. These are known as endemic species.
New Zealand was once almost covered in forest, with hundreds of bird species. As people cut down forests and brought rats, possums, stoats and cats from overseas, 50% of bird species became extinct.
Only four types of frog remain, but tens of thousands of different insects (such as stick insects and wētā) thrive in most habitats. Native eels, water snails, sandflies and crayfish live in the rivers. The only poisonous native animal is the katipō spider, living on sandy beaches.
Plants and fungi
There are 2,500 native plant types, including flowering plants, ferns and conifers. There are also 5,800 types of fungi (such as mushrooms).
The mountains are home to tussocks, daisies, and shrubs with bright berries. Swamps and river banks have rushes, cabbage trees, flax and bulrushes. On the coast, trees like karaka and ngaio have thick, tough leaves that can withstand salt winds.
Some of the forests (kauri, beech and conifer–broadleaf) survive. The conifer–broadleaf forests resemble tropical rainforests, with a canopy, lush foliage and carpets of ferns and mosses.
Facts about native animals and plants
- Apart from two bat species, there are no native land mammals.
- There are no snakes.
- Many species are long-lived: kiwi can live for 30 years, and kauri trees for 1,700.
- Many birds and insects are flightless – they did not need to fly as there were few predators.
- Some species are giants, including kākāpō (the world’s biggest parrot), snails, buttercups and daisies.
- Several trees when young have small, narrow leaves. These only become large when the tree reaches over 2–3 metres. This pattern may have evolved to prevent the giant moa (a bird, now extinct) from eating young plants.