The Continent of ZEALANDIA

New Zealand’s flora and fauna differs from every other large land-mass on earth due to its long isolation and uniqueness as a (near) mammal-free environment. The isolated species living here were affected dramatically around 800 years ago, when humans from Polynesia settled in New Zealand. Not long afterwards the first Europeans arrived and both, with the help of introduced pests, began to deplete species around them and clear vast tracts of land. They brought with them a multitude of mammalian pests. Still chewing the life out of our New Zealand bush, these pests are bringing about a grim ending to an almost inconceivably long history of unique and beautiful life.

170 Million Years Ago map

Drifting Away

Today’s New Zealand landmass originated from a marginal sliver of the Southern Hemisphere supercontinent Gondwana. The first rifts in this supercontinent occurred when Africa detached about 170 million years ago. Forty million years later India (with Madagascar) broke away and the Atlantic Ocean opened up, separating Africa from South America.

Eighty million years ago, the landmass that was to become New Zealand, broke away from Gondwana, splitting away from Australia and Antarctica as the Tasman Sea opened up. Tectonic separation is usually an ‘unzipping’ process and, in terms of today’s maps, the pre-New Zealand rift extended northward from Tasmania through to North Queensland and south along the edge of Antarctica to Marie Byrd Land. This split off an area about ten times the size of present-day New Zealand - a continental fragment called Zealandia. Full separation took over 20 million years with the Tasman Sea reaching its present width of 2,000 km around 60 million years ago.

A Strange Land

This strange land differed from every other large land-mass on earth because of its long isolation and at the time of the first human arrival would have bustled with the strangest life forms all uniquely adapted to life in a mammalian-predator free environment. The largest predator was the magnificent Haast’s eagle, hunting from the air using sight, not smell.  Birds such as kākāpō flourished by evolving to avoid avian predators, by becoming active during the night, camouflaged and pausing motionless when sensing danger.

A range of moa species browsed vegetation using beaks instead of teeth, wētā filled a mouse-like niche in the ecosystem, tuatara, kiwi and many other remarkable and endemic species found nowhere else on the planet adapted over millions of years to survive in New Zealand’s mammal-free habitats.

Humans and rats arrive

Then, approximately 800 years ago, humans from Polynesia settled in New Zealand, hunting birds such as moa and huia as well as seals. They began to deplete some of the species around them (eventually bringing about the extinction of moa) while the establishment of the Polynesian rat, kiore (Ratus exulans), saw several native species facing extinction. 

European sailing ships later brought with them the Norway rat and the terribly successful ship rat and began to clear vast tracts of land. A multitude of pests were introduced, the worst of all being stoats and possums.

Since human arrival, over 50 native species of bird, frog, reptile, bat, fish, invertebrate, and plant have become extinct, some as recently as the 1960s.