Why the species of New Zealand surrendered so easily to the invaders? The answer is simple.
For 85 million years, birds thrived in this land, without any predators threatening them (excluding some raptors) and with a big quantity of space and food available. Imagine so, an entire eco-system based on birds.
- Who eats the leaves on the trees? In Africa they are eaten by giraffes, in New Zealand they were eaten by the Moa, a big ostrich.
- Who eats the grass on the fields? In the rest of the world mammals eat grass (goats, cattle, bison and so on); here the grass is eaten by birds similar to turkeys, among which the Takahè, practically extinct (we took this video in the Zealandia reserve)
- Who looks for worms among the leaves on the ground ? Here small rodents do so, but in New Zealand it is the kiwi (there are still kiwis, even if not many)
If you do not have enemies...
...you do not have to defend yourself, in any way. The animals in New Zealand did not have the need to put into place ANY of the defence strategies elaborated by animals in the rest of the world
- Slowness: they did not have to run away from anyone... they are all so slow!
- Low reproduction rate: many birds in New Zealand lay one egg at a time, often only once a year!!!It was anyhow more than enough to reproduce, since no one was hunting the eggs nor the chicks!
- They do not form flocks: almost all the birds in New Zealand are solitary, at most they made pairs like the kiwis, but they did not form numerous flocks in order to defend themselves from predators.
- They do not have weapons : beaks, feet and so on, are not made neither to defend nor to attack, but just to eat
So, the animals in New Zealand evolved in the most complete peace. They do not have weapons not techniques to defend themselves from predators and this is what brought them to extinction so quickly.