Looking for Kiwi bird facts? This bird is, in simple words, resilient and headstrong. It withstood centuries of predation and habitat loss and is still going on due to its wonderful adaptability.
Kiwi or the kiwi bird is flightless. It is native to New Zealand. It belongs to the genus Apteryx. Though it is a bird, it has more in common with mammals than birds.
Kiwi bird is the smallest living ratite found to date. Kiwis have amazing memory; they can remember things for a minimum of 5 years. You really can’t fool this guy. Let us learn many more such fantastic kiwi bird facts.
Kiwi Bird Facts: Etymology
There are two theories behind the word kiwi. One of the theories suggests that kiwi is a word from Māori language which means “of imitative origin”.
The second theory says that kiwi word arises from Proto-Nuclear Polynesian word kiwi.
According to this theory, there is a bird in tropical Pacific islands called Numenius tahitiensis or Bristle-thighed curlew that resembled kiwi.
When the Polynesian settlers came and settled in New Zealand, they saw this ‘new kiwi’ bird and named it “kiwi”.
The genus of kiwi bird is Apteryx which is a Greek word meaning without a wing for the simple fact that kiwi is a flightless bird.
Another story is that kiwi’s cry sounds ‘kee-wee-kee-wee’. The bird is said to be named after its cry.
Earlier, kiwi birds were thought that the kiwis were closely related to the moas which are also flightless birds.
Recent DNA studies proved that kiwi is more closely related to Madagascar’s extinct elephant bird.
Among the extant species (species which are living), the kiwis are closely related to cassowaries and emus than to moa (an extinct species).
It is believed that Proapteryx (now extinct species) was capable of flying came to New Zealand independently flying.
These birds flew to New Zealand and they are smaller than the moas which were already present when kiwis arrived.
There are 5 known extant species of kiwi birds. They are briefly described as follows:
Apteryx australis – This species is commonly known as Tokoeka, common kiwi, or southern brown kiwi. It is mostly limited to South Island.
Apteryx mantelli – The vernacular name of the species is North Island brown kiwi. As the vernacular name suggests, It is mostly seen in North Island.
Apteryx haastii – Also known as Roroa or great spotted kiwi. It is seen in New Zealand.
Apteryx rowi – This species is popularly called Okarito brown kiwi, the rowi, or Okarito kiwi. It is widely present in South Island.
Apteryx owneii – It is generally called little spotted kiwi. It is usually seen in Kapiti Island.
Kiwi Bird Facts: Description
In this section of kiwi bird facts, we will learn why the kiwi birds are flightless along with the basic and general description of the kiwi bird.
Kiwis do have wings but they are vestigial organs of its body. The wings are so small as they are nearly invisible under their hair. Wings measure only 1 inch.
Just like other ratites that are ostrich, rhea, cassowary, etc., kiwis don’t have sternum (breastbone) and keel (extension to the breastbone) to support wings.
One of the most interesting kiwi bird facts is that the bones of kiwi birds are filled with marrow. This is not usually seen in birds to help birds in flight.
Kiwi birds don’t even have a preen gland or oil gland. The feathers of kiwis don’t have aftershafts and barbules.
The eyes They have vibrissae or whiskers around the bill or gape. They have mere 13 flight feathers, don’t have a tail and pygostyle (fused caudal vertebrae to support tail).
The bill of kiwis is sensitive to touch, pliable, and long. Their toes (four in number unlike other ratites which have three) and claws are immensely strong.
The gizzard of the stomach is weak and the caecum is narrow and long.
Kiwi’s legs are strong and weigh two-thirds of kiwi’s weight.
The height of kiwis ranges from 14 to 18 inches to 20 to 25 inches.
Brown kiwi has the highest weight and little spotted kiwi is the smallest kiwi.
With an average weight of 1.4 to 5 kilograms, brown kiwi is the heaviest and with just 0.8 to 1.9 kilograms, little spotted kiwi is the lightest of all kiwis.
Don’t be under the impression that they can’t run fast. They can easily outrun a human. It is also wary of humans and other animals.
The body temperature of kiwis is similar to mammals. The temperature of kiwi is around 38 degrees Celsius or 100 degrees Fahrenheit.
In relative terms, the eyes of kiwi are the smallest to the body mass of all birds. It also means that they have the smallest visual field.
Kiwis are mostly nocturnal but they rely mostly on other senses than on their eyes.
Their eyes are extremely underdeveloped that blind kiwis are also seen in nature. This shows their low dependence on sight for foraging or even survival.
Many studies were conducted which showed that kiwis had eye lesions or were completely blind but otherwise completely healthy.
The extinct species, elephant bird (closest to kiwi birds) also shared this characteristic.
However, there is no evidence of any complex behavior of kiwis.
Habitat and diet
The behavior of endemic species of New Zealand changed with the arrival of humans and other animals.
The nocturnal behavior of kiwi is mostly due to the invasion of invasive animals and humans.
The kiwis which are in a sanctuary or the areas which are not predators are removed are seen in daylight.
They usually prefer temperate and subtropical podocarps (conifers of the southern hemisphere) or beech forests.
They use burrows to hide, rest, and escape. They use multiple burrows.
They had to adapt to other habitats such as tussock grassland, mountains, and the sub-alpine scrubs.
Kiwis’ olfactory senses are well developed (unusual in birds). These are the only birds that have nostrils at the end of their beaks.
They use their sense of smell to hunt small insects, plants, berries, and animals. They also use other senses like hearing (they have big ears) to help in hunting.
One of the funny and weird kiwi bird facts is that they tip their head towards the source of sound just like humans.
The kiwis are protective of their territory just like any other animal. A kiwi patrols in its territory and leaves markings to mark their property.
They communicate with each other via half scream and half whistle, shriek, snort, hiss, grunt, etc. which is also used to ward off other animals.
Kiwi Bird Facts: Reproduction
The kiwis take 16 months (for males) to 3 years (for females) to become sexually active.
Kiwis are monogamous for either 20 years or their entire lives. The mating season lasts from late winter to early summer.
Male kiwis are not usually appealing in their appearance neither are their voices sweet, so, their only option of securing a mate is by stalking.
The female kiwi may accept the male kiwi or the female just kicks the male out to scare the male kiwi off.
Once the male and female kiwi become ‘couple’, the male either dug burrows or use hollow logs and use them as a nest.
It is interesting to note that the female kiwis have two functional ovaries unlike most of the birds which have only one functional ovary (the left one).
The females lay around 1 egg at a time sometimes two or three per clutch (litter). The eggs are either off-white, white, or pale green.
Did you know that female kiwi can produce 100 eggs in their lifetime?
The eggs of kiwis are huge when compared to bird and egg ratio. The eggs maybe around 20% of their mother’s weight. To give you an idea, the kiwi eggs are 6 times a chicken egg, and the size of chicken and kiwi is almost the same.
You may not think that the above kiwi bird fact is not really jaw-dropping but just imagine a 54-kilogram human giving birth to an 11-kilogram baby! The human baby weighs around 2.5 to 4.5 kilograms on average. Go figure!
Another of the many interesting kiwi bird facts is that the males hatch the eggs with the only exception of great spotted kiwi. In this species, both the parents are involved.
Female kiwi’s food consumption increases three times the normal to support egg development in its body.
The eggs of kiwis contain double the quantity of yolk when compared to the birds of kiwi’s size.
When the eggs are hatched, they weigh 255 to 300 grams.
The eggs also have antifungal and antibacterial properties. This is extremely essential because kiwi lays eggs in damp grounds where bacteria and fungus grow without any restrictions.
When the question comes that why and how come they can lay such a massive egg, the answer is not simple. It may because of many reasons such as having a lot of food, kiwis being flightless, lack of predators, etc.
The incubation period is a little long (from 74 to 90 days). It is believed that ancestral kiwi decreased in size (to the present size) but the size of the egg remained the same. The chicks that are born need less parenting.
The chicks lack an egg tooth so they have to push their way through the eggshell. The chick has adult feathers and they look a baby version of its parents.
The chick has yolk in its abdomen and it gets the nourishment from there (parents don’t feed the baby).
The chick stays in the nest for a few days and once it gets enough strength, it comes out and tags along with his/her father in the hunt for food.
The chick stays with father for around 20 days and the chick may stay in the territory of his/her parents from months to even years.
It is now proved that kiwis do divorce! Yes, they divorce after staying together for a couple of years.
The divorce rates increase in the areas where kiwis are abundant.
Relationship with humans
Māori tribe believed that the kiwi birds were protected by the God of Forest, Tane Mahuta.
This tribe used to consume the meat of kiwi birds and used its features for adorning the ceremonial cloaks which were called kahu kiwi.
Feathers of kiwis are used for Kahu kiwis or other purposes. The only difference is in today’s world, feathers of those birds are used which die ‘naturally’ such as predation, road accidents, or from captive birds, etc.
These birds are no longer hunted and Māoris consider themselves as guardians of kiwis.
In 1851, the London Zoo became the first zoo to keep a kiwi. In 1945, the first-ever captive breeding took place.
As of 2000, 13 zoos are functional outside New Zealand which keeps the zoo. Some of the zoos are the Frankfurt Zoo, Walsrode Bird Park, San Diego Zoo, Smithsonian Conversation Biology Institute, Columbus Zoo, etc.
New Zealand used kiwi image on its regimental badges. Soon after this, many military regiments such as Hastings Rifle Volunteers and South Canterbury Battalion followed suit.
It was in the first world war that New Zealanders were called kiwis. The usage has become extremely popular and almost everyone uses it today.
The image of kiwi, since then, is used in many clubs, organizations, coat of arms, crests, badges, etc.
The national team of New Zealand rugby team’s logo features kiwi. Royal New Zealand Airforce also uses the image of kiwi.
Kiwi featured on the reverse side of three coins of New Zealand. New Zealand’s dollar is termed as kiwi in currency trading.
Kiwi Bird Facts: Conservation
Three of the five species are listed as endangered by IUCN and the rest two species were listed as vulnerable (earlier to 2017, the two species were also listed as endangered).
Studies across New Zealand prove that the survival rate of chicks is a mere 5-10% in the wild. However, the survival rate significantly increases when there is the management of chicks by humans as in sanctuaries.
In 1908, New Zealand passed a law that prohibited killing, capturing or hunting of kiwis. They even charged $100 as a penalty.
In 1921, the kiwi was declared as an ‘absolutely protected bird’.
In 2000, New Zealand’s Department of Conservation started 5 sanctuaries to protect kiwis. Haast Kiwi Sanctuary, Moehau Kiwi Sanctuary on the Peninsula of Coromandel are two of the five sanctuaries.
Apart from these five sanctuaries, mainland conservation islands have been set up to protect kiwis.
Laughing owl, which is now extinct, was the only natural predator of kiwis. However, many animals like dogs, stoats, cats, etc. have become a threat to kiwis.
The stoats go for kiwi chicks and dogs usually hunt adult kiwis.
80% of the kiwi’s habitat stands destroyed today. It is saddening to say that almost 10% of decrease is observed in kiwi’s population every two years!
In the wild, kiwis can live up to 50 years in the wild and 30 years in zoos.
We guess you are just in awe with this little guy here (just like us) after reading kiwi bird facts. If you have anything to add or if you think we missed something, do drop a comment below.