New Zealand's Unusual Biodiversity

This unusual biodiversity is due to long isolation from other continental landmasses – about 80 million years.

It is estimated that New Zealand has 80,000 species of native animals, plants and fungi. Of these, a great many are endemic – that is, not naturally found anywhere else in the world:

• More than 90% of insects.
• About 80% of sap-bearing plants.
• About 25% of all bird species.
• All of New Zealand’s native frogs and reptiles.

By comparison, Great Britain has only two endemic species – one plant and one animal.

Many extinctions

Since people arrived, New Zealand has experienced one of the highest species extinction rates in the world, due to lost habitats and the introduction of pest plants and animals. Among the most well known extinct birds are the huia, Haast’s eagle and moa. Almost 2500 native land-based and freshwater species are listed as threatened today.

Dominated by birds

A key reason for New Zealand’s unusual native biodiversity is the lack of land mammals.

Until people and other warm-blooded mammals arrived, New Zealand was dominated by insects and birds, and there were no land mammals except for bats for millenia (in 2006 it was discovered that mammals did in fact exist in New Zealand until about 19-million-years-ago).

The absence of land mammals meant birds were left to adapt and fill the niches that elsewhere in the world mammals fill. One of these birds is the kiwi, sometimes described as an honorary mammal because of its unbird-like attributes.

Kiwi are a ratite and, even though they are New Zealand's national icon, there is still some debate over just how they came to be here.