Our changing ecosystems – timeline
A look at some of the historical changes in New Zealand’s unique ecosystems and steps being undertaken to protect it.
250 million years ago – One landmass and one huge ocean
All landmass on Earth is grouped in one super continent – Pangaea. The remainder of the surface of the planet is covered in water, in the form of vast oceans. Around 250 million years ago, Pangaea begins to break up due to the pressures from under the Earth’s crust.
230 million years ago – Dinosaurs begin to roam the Earth
Dinosaurs start to appear in the fossil record during the Triassic Period (250–200 million years ago). Dinosaurs evolved from the species archosaur, following a mass extinction of an estimated 95% of all life on Earth (the Permian-Triassic extinction). Over the next 160 million years, they are the dominant species on Earth and differentiate to fill every ecological niche.
Dinoflagellate fossils
The presence of these two fossil dinoflagellates in a rock can help date it to the late Cretaceous. The fossils are only about 200µm long.
Micrograph by Poul Schioler.
180–200 million years ago – Gondwana and Laurasia begin to form
When the enormous landmass Pangaea begins to break up, it forms two smaller landmasses – Laurasia in the north and Gondwana in the south. The fossil record from southern continents such as Africa, Australia and South America show that these were all originally part of the same huge continent. Gondwana finally separates from Laurasia around 180 million years ago.
120 million years ago – New Zealand begins to form
The land that will eventually form New Zealand starts to separate from Gondwana. A rift begins to develop in the huge Gondwana landmass. As the rift deepens, the ocean floods in, forming the Tasman Sea. The rift and the sea continue to grow, pushing New Zealand further south until around 30 million years ago.
Tectonic plates
This animated video shows the movement of the tectonic plates that make up the Earth’s crust.
Starting 600 million years ago, watch continents form and break apart as the plates move. Pangaea the supercontinent, split up at about 220 million years ago into Laurasia and Gondwana both of which broke up again. Gondwana which comprised Australia, Antarctica (including New Zealand), India, Africa and South America started breaking up about 150 million years ago. Australia departed from the Antarctica group at around 50 million years and around 35 million years ago South America moved away leaving Antarctica to move towards its current position.
80 million years ago – Meteors strike the Earth and cause massive extinctions
A huge meteor hits the Yucatan peninsula in Mexico with enough force to form a crater 170 kilometres wide (about the width of the South Island between Greymouth and Kaikoura). The meteor impact causes a range of catastrophic events including tsunamis, volcanic eruptions and so much debris in the atmosphere that the Sun’s rays don’t reach the Earth’s surface for at least 6 months. By this stage, an estimated 85% of all the world’s existing species are extinct.
From 65 million years ago – New Zealand is an island
Now separated from the continents, the newly formed island is inhabited by species from Gondwana, including beech trees, ferns, kiwi, moa, tuatara and wētā. There is evidence of early mammals elsewhere in the world but it appears that none survived here and NZ became dominated by birds.
25 to 5 million years ago – New Zealand as we know it formed
Various geological events occur including sinking followed by huge upheaval. Around 5 million years ago, the landmass begins to split up forming the Cook and Foveaux Straits. Species continue to travel from nearby Australia such as mānuka, rātā, pōhutukawa, saddleback, kōkako and huia.
7000 years ago – Native New Zealand species established
The islands of New Zealand have taken their current form and are covered in diverse, mature ecosystems with a multitude of wildlife. Birds dominate and with few predators, many lose the ability to fly. The predators that do exist are huge bird species such as the Haast’s eagle.
Haast’s eagle
This giant Haast’s eagle used to prey on moa. When the numbers of moa decreased, this huge predator died out forever.
950–1150 AD – Polynesians arrive
The first Polynesian settlers bring with them the Polynesian rat (kiore), which wipes out a number of small bird species as well as frogs and lizards.
1400 – Haast’s eagle becomes extinct
The female eagles weigh 10–15 kg, the males 9–12 kg, and both have a wingspan of around 3 metres (relatively short, given their weight). This means they are powerful fliers, reaching estimated speeds of 80 kph, with a great deal of manoeuvrability, allowing them to hunt moa in the dense forests. As the number of moa declines, the Haast’s eagle becomes extinct.
1500 – Last of the moa disappear
Hunted for food and affected by habitat destruction, the moa are very rapidly lost forever. Some think the moa may have survived for less than 200 years from the first arrival of humans.
1642 – Abel Tasman sights New Zealand
New Zealand is first sighted (and given its European name) by explorer Abel Tasman.
1769 – Captain Cook lands
Europeans first set foot in New Zealand with Captain James Cook.
Mid-1800s – Europeans begin to settle in New Zealand
Foreign species such as rats, cats, stoats, weasels and ferrets are introduced. Species of frogs, lizards and small birds become extinct. Humans hunt seals and whales. New Zealand loses an estimated half of its invertebrate (for example, insects) and bird species.
Rats eating eggs
Rats are adapted to climbing trees and can locate nests easily due to their strong sense of smell.
1894 – Last Stephens Island wren killed by cat
The island’s lighthouse keeper reports that his cat has brought him 17 tiny flightless birds, about the size of a mouse. The Stephens Island wren is discovered and then becomes extinct within the space of a year – the only bird known to have this happen.
Mid-1890s – Off-shore islands used in conservation
Resolution Island caretaker Richard Henry moves kiwi and kākāpō to the island to prevent them being attacked by predators. Unfortunately, stoats swim to the island, and the conservation attempt fails.
1907 – Last confirmed sighting of the huia
The feathers of this small bird are highly prized by Māori – the huia are easily identified by their sleek black plumage, white tipped tail feathers and a bright orange wattle under the neck. Their call is said to have been deep and melodious, similar to the distinctive call of the tūī. This native bird is thought to have been hunted to extinction by rats and stoats. The last confirmed sighting of the Huia was in 1907, though there have been reports of unconfirmed sightings since then.
The extinct huia
The last confirmed sighting of the huia (Heteralocha acutirostris) was in 1907. This illustration from Sir Walter Buller’s A History of the Birds of New Zealand shows a male and female huia perched in a tītoki tree.
1948 – Takahē rediscovered
Once thought extinct, amateur ornithologists discover takahē in the South Island's remote Murchison Mountains.
Find out more about this famous rediscovery and the huge effort that has gone into boosting the takahē population in the article Takahē conservation efforts.
Takahē in tussock
Wild takahē populations live among the snow tussocks of Fiordland’s isolated Murchison Mountains. Takahē have adaptations that mean they can survive in harsh conditions.
1960s – More last sightings
Last sighting of the bush wren, the South Island snipe and the South Island kōkako.
1980 – Tiritiri Matangi Island designated a scientific reserve
The land on Tiritiri Matangi Island, off the coast of Auckland, is slowly converted from pasture to bush land, having been farmed since the 1890s. Bird species are slowly re-introduced, and from the mid-1990s, the island is open to the public.
1995–1996 – On-shore ‘islands’ established
The Department of Conservation begins to establish 6 on-shore ‘islands’, including the Trounson Kauri Park and Rotoiti Nature Recovery Project. These regions of the mainland have all introduced predators removed before fencing, and other measures are undertaken to prevent predator invasion.
Ecology of New Zealand
Dr Peter Buchanan and Dr Robert Hoare, scientists at Landcare Research NZ Ltd, talk about New Zealand’s unique ecosystem. They talk about why so many of the species found here aren’t found anywhere else in the world.
1990s onwards – additional mainland islands established
Additonal sanctuaries, such as ZEALANDIA and Orokonui Ecosanctuary are established. All introduced predators are first removed, a predator-free fence is erected and an active pest predator management programme is maintained. These sanctuaries have had a notable halo effect and helped increase public awareness of our native species.
Zealandia Te Māra a Tāne
Zealandia Te Māra a Tāne in the heart of Wellington City was conceived in 1995 and opened in 2000 after the erection of an 8.6 kilometre long predator proof-fence. The sanctuary has a 500 year plan to restore the reserve to how it would have appeared before humans arrived in New Zealand. It is home to many endangered species of birds, plants and animals such as saddleback, tuatara, giant wētā and little spotted kiwi.
2016 – Predator Free 2050
In 2016 the government anouncment the Predator Free 2050 plan.
This is the most ambitious conservation project attempted anywhere in the world, but we believe if we all work together as a country we can achieve it.
Prime Minister John Key
2018 – Numbers of threatened plant species increase
The number of vascular plants that are now nationally threatened increased to 14%, (in 2012 it was 11%). Kauri is also now classified as Threatened – Nationally Vulnerable on the New Zealand Threat Classification System, this is the first time and is due to spread of kauri dieback. Explore Conservation rankings further.
2020 – More islands declared pest free
Rakitū Island in the Hauraki Gulf declared predator-free, offering sanctuary to species such as pāteke, kākāpō, the little blue penguin and the grey-faced petrel. There are now over 40 pest-free islands in this area.
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