Facts About The Kiwi
Kiwi fascinate scientists because although it is a bird it has features more characteristic of a mammal.
- It has tiny wings, but cannot fly.
- It has feathers that are more like fur.
- It is the only bird in the world with nostrils at the end of its beak.
- Its sense of smell is second to none.
- It has no tail feathers, but does have whiskers, like a cat.
- It has marrow in its bones, just like a human.
- Very unusually, females have two ovaries, most birds have only one.
Kiwi - a creature of the night
Most kiwi will sleep away the day time in a burrow. They are nocturnal which means they come out after nightfall when they come out to forage for food under the protection of the night.
This is when they will find a huge array of food – insects, grubs, earthworms, fallen fruit and native plants.
Other night birds are equipped with big powerful eyes so they can see at night. The kiwi is different, its small eyes do not see as well at night.
Instead it feels, smells and hears its way around. Its big ear openings provide a very good sense of hearing and the long graceful whiskers and sensitive bill help it locate food in the soil and leaf litter.
Far from being a shy night creature, kiwi are bold and territorial - superbly adapted for life in the forest.
In the forest you can hear it before you can see it
The kiwi is often given away by the sound of its uniquely placed 'noisy' nostrils at the tip of its bill. As it walks it taps the ground with its bill, probing the soil and sniffing loudly.
It has a well developed sense of smell because the part of the brain controlling this sense is much larger than in other birds and is more like a mammal's structure.
Perfect camouflage
Kiwi feathers are different to those of most birds. From a distance they look more like fur, although when stroked you can feel the feather structure. The feathers hang loose, they keep the rain out and the warmth in. Unlike other birds the feathers molt throughout the year and are constantly being renewed.
The feather patterns allow kiwi to disappear into the dark and fade into the forest vegetation. When distressed a kiwi freezes, disguising itself from aerial predators.
Largest egg in the world
It takes between 16 months to three years for birds to be sexually mature enough to breed. Breeding usually occurs between July and February. The female North Island Brown kiwi has two functional ovaries which is unusual in the bird-world. The kiwi egg is the largest in the world in relation to the size of the bird laying it, it also contains the largest proportion of yolk. Incubation is done by the male and can take anything from 74-90 days.
Kiwi chicks are instinctive feeders and are not taught by parent birds to forage for food. When first hatched, the belly of the chick is swollen with yolk which will sustain them for their first few days.
Other facts about the Kiwi you might not know:
- The Kiwi egg is the largest in the world, relative to the bird laying.
- Kiwi are omnivorous and although worms form a major part of their diet, they will also readily eat woodlice, millipedes, centipedes, slugs, snails, spiders, insects, seeds, berries and plant material.
- Kiwi feed at night and probe into the ground with their bill up to a depth of 12cm.
- Stoats, ferrets and weasels are the biggest threat to the survival of Kiwi, closely followed by cats and dogs – only 5% of all Kiwi hatched in the wild survive to adulthood.