Has the kiwi always been a flightless bird?
Kiwis along with many other New Zealand birds are flightless. There are no native terrestrial predators in New Zealand. The introduction of cats, weasels and rats has devastated the bird population. I do not know the evolution of the kiwi but it only has rudimentary wings. Ostriches, which have never been able to fly, have much larger wings in proportion to body size. While all birds have feathers, not all can fly and some have never been able to do so. The kiwi could be descended from flightless birds. On the other hand, as New Zealand is a group of islands, the birds had to get there somehow, even the flightless moas, some of which were as tall as humans. The probability is that the ancestors of all New Zealand’s birds flew there. By the way, the singular of “species” is “species”. “Specie” means “money”.
