How Kiwi Came Here

This means kiwi developed outside New Zealand, after it split off from Gondwana, and migrated here later.  It is thought they arrived about 60 million years ago, but just how that journey happened remains a mystery.  

Three explanations have been put forward.

An ancient ancestor

Some suggest the kiwi’s ancestor was already around when New Zealand broke away from Antarctica and Australia. 

If true, it removes the question of whether or not the kiwi could ever fly.  It would also mean our national icon originated around the same time as the dinosaurs.

Walking to New Zealand

Islands rise up and submerge as tectonic plates move. A string of islands have come and gone between New Caledonia and Northland during the past 50 million years. It is possible that the kiwi and other species moved from one island to the next as they rose and fell – using them like stepping-stones to reach New Zealand.

A variation on the theme is that, because New Zealand was once connected to Australia as part of Gondwana, kiwi’s ancestors simply walked across before the split.

A flying kiwi

A flying kiwi is the least likely explanation. Of all today’s ratites, only the South American tinamous can fly - and it can’t fly very well. While some debate has recently arisen, prevailing opinion is that all ratites had a flightless ancestor – which makes the tinamous the exception, not the rule.

Another reason why kiwi probably never flew is the theory that its ancestor was much bigger than today’s bird. The kiwi egg is so huge it should theoretically be laid by a bird two or three times bigger – closer to a cassowary in size. 

And that would have been much too big to fly across the Tasman Sea, even millions of years ago when the gap was much narrower.