BROWN KIWI

BROWN KIWI

Scientists are of the opinion the brown kiwi behaves more like a hedgehog than a bird. The opinion even goes so far to think the bird went through an evolution to be more like a mammal. After all they point out it live in a country where there were no mammals. Therefore the bird had no competitions food wise. New Zealand only introduced mammals recently

It had been established that the bird evolved long before mammals and it is even thought it derived from dinosaurs, only the small bird-like dinosaurs. Most birds grew wings and learned to fly. To fly is very useful but is uses a lot of energy. The birds which learned to fly are able to migrate to avoid cold winters or just cover distances for various reasons.  When they learned to fly they have to keep their feathers in top condition and renewed them every year. During their evolution they had to develop strong muscles and various sizes of wings with special wing feathers, Therefore they had to find a lot more food than birds staying on the ground.

It is Assumed the kiwi must have reach New Zealand at a time when the country was still connected to other countries. This assumption leads to the result that the kiwi is there about 80 million years. Once the land masses were broken the birds could develop without competition or predators.

Till the time when the Maoris arrived a few hundred years ago the country had only two mammals which were bats and they had flow there.

NIGHT HUNTERS

Since there were no mammals and no competitions for food the kiwi had no problems in that direction. There were larger birds of prey and they were dangerous predators. Therefore the kiwi must have developed it hunting habits and does at night. The other reason is that beetles and slugs are active at night to avoid the heat during the day.

The kiwi eyesight might not be very good and is not necessary for its night hunt. However, it can run very fast through the undergrowth at night and therefore it must be better than thought. 

To hunt at night the bird must have a great hearing and smell which are necessary. It is assumed that most birds have no or very little sense of smell. The kiwi has air passages on top its peak. Therefore it must use it to find food and going through vegetation and dig in soft grounds.

RUNS AT HIGH SPEED

The kiwi has wings which it covers under its feathers. Therefore the assumption is that way down its history it must been able to fly. Now the wings are only small vestiges and it is lacking the specially breastbone with flight muscles. It also doesn’t need its plumage streamlined its feather are rather loose. The bones are heavier and stronger which prevents fractures easily. A further advantage the kiwi has stronger legs and feet which help when running

Even New Zealanders have hardly seen a kiwi because they live in forests and undergrowth and hunt at night.

BREEDING

Observations revealed that kiwis live in pairs. The female produces the biggest egg or two in accordance to its size. It is about a quarter of the female weight and about 450g. After laying the egg the male incubates for about 10 to 12 weeks the nest. He does it without any help from the female at all.  The reason behind it could be that the female has used so much energy to produce the egg she has to go and feed herself again. If she were to sit on the nest as well the length of time she would die of starvation.

When the egg is hatched the chick has a yolk sac from which it feeds. Birds which produce only one offspring take great care and make great effort to rare its young. The kiwi it is thought they leave the young to fend for themselves. It is thought since there were not predators it was safe to do so.  Then humans arrived and they brought with them rats, dogs, pigs and other mammals. This destroyed many flightless birds of the country. The brown kiwi has coped with the problems quite well so far. The great spotted and less spotted  kiwi were heading for extinction and are now put on islands on which there no mammals.