New Zealand has a large number of animals and plants that are classified as threatened, meaning they’re at risk of becoming extinct in the near future.
In this section:
- Why do some species become extinct?
- What’s the biggest threat to NZ species?
- How do we know which species are threatened?
Why do some species become extinct?
Extinction can happen very suddenly or occur gradually over thousands of years. Species have been going extinct since the world began, either because of naturally-occurring environmental conditions or as a result of human actions.
The main human actions that cause extinction are over-harvesting, pollution, habitat destruction, and introducing pests and weeds.
What is the biggest threat to NZ species?
New Zealand’s native flora and fauna are particularly vulnerable to predatorial mammals, many of which were introduced by settlers in the late 1800s. Possums, rats, and mustelids such as stoats, weasels and ferrets pose a significant threat.
For more information on common predators, see our Predators section.
How do we know which species are threatened?
New Zealand has its own classification system for identifying threatened species.
The risk of extinction is confirmed based on several benchmarks, including the population size, the rate of growth or decline, and how long it has been in New Zealand. Over a period of time the numbers are reviewed to see whether anything has changed.
There are seven categories, ordered by the most to the least threatened:
- Nationally critical
- Nationally endangered
- Nationally vulnerable
- Naturally uncommon
Several species have been classified as either nationally critical, nationally endangered or nationally vulnerable in New Zealand, including reptiles, frogs, bats and birds. Birds are considered ‘nationally critical’ when fewer than 250 mature birds are left or their population has dropped more than 70% over 10 years (or three generations, depending on which is longer).
Below are some examples of New Zealand’s most threatened birds. For a more comprehensive list, visit the DOC website.
The kakapo (or night parrot) is one of New Zealand’s most well-known threatened birds, with only about 125 left. They create their nests on the ground, making them extremely susceptible to predators such as cats, rats and stoats.
The ground-dwelling takahe was once believed to be extinct before it was discovered again in 1948. Safe areas were introduced and the population rose until 2007, when a plague of stoats overran the Murchison Mountains. Within a few months the population was halved, and stoats and other predators continue to be a concern for these vulnerable birds.
The yellow-eyed penguin lives on the coast of Stewart Island and bottom of the South Island, as well as the subantarctic islands. It is considered to be the world’s rarest penguin. Predator threats such as dogs, cats, rats and stoats cause the species to be critically threatened,
North Island brown kiwi (classed as nationally vulnerable)
The North Island brown kiwi is New Zealand’s most common kiwi. It has a steady rate of reproduction but, due mainly to predators such as stoats and ferrets, it is declining by 2-3% every year. As a result, it is at risk of disappearing from the wild within two generations.