Your Kiwi Questions Answered

There are five different species of kiwi, all of which are flightless and unique to New Zealand. The kiwis at the National Zoo are North Island brown kiwis, the only kiwi species that can be seen outside of New Zealand. All five species are endangered or vulnerable to extinction. The total number of kiwis is about 70,000.

Most kiwi species live in pairs and form very long pair bonds (some have been documented at 20 years).

Cocks, hens, and chicks.

Once a kiwi is an adult, it locates a territory and typically spends its whole life in it.

Besides habitat loss, the biggest threat caused by humans is introduced animals to the islands—prior to the arrival of people, there were no terrestrial mammals that could prey on these flightless birds. Dogs are the number-one predator of adults. Stoats and cats lead for the predation of the juveniles (up to 90 percent in some unprotected areas). Kiwis are also hit by cars.

New Zealand is working quite hard at re-establishing native bush, plus several islands around the main islands are being used as mini rescue islands for kiwis and other endangered and threatened species. The biggest threat to kiwis remains the introduction of the mammals to New Zealand, especially dogs, cats, and stoats. There are several programs working on reducing and eliminating these pests.

New Zealand is about 89 million years old and has been separated from any other land masses for that long. At New Zealand's beginning, it had no mammal species (except for three species of bats). This allowed the birds to become the primary movers and shakers on the islands. With no mammals, many birds found it advantageous to give up flying—they didn't need to escape from terrestrial predators. Flight is very costly to maintain.

All kiwis live in New Zealand. It depends on the type of kiwi that you are talking about when it comes to habitat preference. North Island brown kiwis prefer temperate forest with native bush, but due to habitat changes they are found in a variety of places including abandoned farm land. Kiwis have lived on all the three major islands of New Zealand.

You can hear what the male and female sound like on this page (scroll down the page).

It is fertilized in the very early stages of development. The first egg usually takes about 34 to 36 days to fully form and be laid, the second egg takes about 26 days. Some kiwi experts think that a female kiwi may be able to retain the sperm for a long period of time.

Kiwis have three forward-facing toes, and one back-facing toe, and a smaller spur on the back.

They usually breed during spring and summer months. Even outside of New Zealand, kiwis keep to this schedule (fall and winter months in this hemisphere). North Island brown kiwis can lay eggs every month of the year, but typically they do so in spring and summer.

Once a year, usually producing one egg.

The simple answer is no, for several reasons. All kiwis are are endangered or vulnerable to extinction, and they are protected in New Zealand. Also, they are not social animals. They do not even get along with other kiwis, except for their mates.

Wild kiwis are omnivores. They eat a variety of different insects, including worms (more than 190 types in New Zealand), wetas (a family of nocturnal insects endemic to New Zealand), larva, and crayfish. About 80 percent of their diet is made up of insects. They also eat berries, roots, and fruit.

Good question. No, both of the kiwis that we use in our program have been conditioned to doing the program. We started out by doing smaller and short sessions and gradually lengthened the session and the number of people in the audience. We also make it a positive experience by putting earthworms in the kiwi box while we do the demo. Also, we don’t do the demo under bright lights or out in the sun but in shaded areas, which I think makes it more comfortable for them. Daily programs

I think all species are special in some way, but the five kiwi species are different from most other birds in several ways. They are the only birds with nostrils located at the end of their bill. They have the second best sense of smell of all birds. They have special feathers around their faces that help them find their way about much like cats and dogs whiskers do. They have solid bones, compared with most other birds, whose bones are hollow. They also lay the largest egg-to-body-weight ratio. These are just some of the special adaptations that kiwis have.

Interesting question. There are very few raptor species in New Zealand. On the South Island, there once lived the world's largest bird of prey, the Haast's eagle, whose talons were the size of a tiger's claw. These eagles hunted species of moa, large flightless birds, All moas, including one species that weighed up to 500 pounds, and the Haast's eagle are now extinct. An owl, called a morepork, has been housed with a kiwi in some zoos, but sometimes the kiwi has killed the owl. The kiwi was not really bothered by much until people arrived, bringing dogs and other animals with them.

It's fun to watch Manaia scurry around his enclosure so quickly. Will he maintain this activity level as he matures? Also, at what age will a mate be introduced?

It's hard to say but I think he will eventually slow down. Males tend to mature faster than females, at about two or two and a half years old. Regarding your other question, unfortunately outside of New Zealand there are very few females, so he will go on a list. But hopefully, as the zoos that have kiwis outside of New Zealand succeed with their breeding efforts, he won't have to wait too long.

I don’t believe anyone can give a definitive answer as we don’t really know how long kiwis live. We believe kiwis can live up to 60 years, and females may lay their first egg at three to five years of age. Different kiwi species have different clutch sizes. The North Island brown kiwi (the species we have) can have up to four eggs per season, but most kiwi species lay only one egg per clutch. Some kiwis may lay up to 100 eggs in a lifetime, although they may not all hatch or survive.

Great question! Scientists have recently discovered that the bill tip houses a sensory organ that detects tiny vibrations from worms and other invertebrates. This sensory organ has also been found in wading birds. The kiwi will widen the probe hole to a funnel shape when the bird is chasing prey deeper in the soil than the length of the bill.

Sometimes to achieve a deeper probe the bird will leap into the air momentarily, using its body weight to bury its bill to the hilt. The nostrils located near the tip of the bill of the upper mandible are very efficient at sniffing out food. No other bird has nostrils as extended as this; the only other bird in the world with a better sense of smell is the condor (based on the size of the olfactory bulb, which determines the sense of smell). Studies have shown that the kiwi can detect worms lying several centimeters under the surface. In addition to worms, the kiwi will eat spiders, slugs, snails, woodlice, centipedes, and millipedes, among other animals. Kiwis round out their diet with berries and seeds of forest trees. They will also eat freshwater lobsters (crayfish) and baby eels.

If you are talking climate-wise, yes. But when you consider that they evolved with no mammal predators, then the answer is no. That is the number-one problem in New Zealand for these birds. We are not 100-percent sure about the lifespan of a kiwi, but we think 60 years is possible. So I would have to say once a kiwi is in the late 40s, it is an aged bird.

The number-one predator of adult kiwis is dogs, and the main predators of juveniles are stoats and cats. A relative of weasels and also known as ermines, stoats were introduced to New Zealand in the late 19th century to control the rabbit population. Today, they kill about 60 percent of all North Island brown kiwi chicks. Kiwis also suffer from habitat loss, but the primary threats are animals introduced to New Zealand.

It depends on the species. Kiwis are found from the coast to low-alpine zones 1,500 metres above sea level and across 13 degrees of latitude (34 to 47 degrees south). The five species of kiwi occupy a vast range of habitats—indigenous forest, shrublands, wetlands, coastal dunes, tussock grassland well above the treeline, regenerating native habitat, and planted conifer forests. If predation and human development are tolerable, kiwis will survive in a mixture of habitats. The Haast Tokoeka live in low-alpine tussock grasslands between 1,000 and 1,500 meters above sea level, in spring and winter snow can lie for weeks above the treeline, burying burrow entrances and forcing the birds to tunnel through the snow.

They have developed the second-best sense of smell of any bird and that wonderfully long bill to probe for insects. Their coloration has become dark, a definite asset for a nocturnal animal. They have extremely powerful legs for digging out burrows and for fighting other kiwis that might invade their area. Their very long rictal bristle feathers around the face resemble whiskers with which they feel around in their environment (just like cats and dogs do). Their hearing is excellent, which helps them listen for their mate or other kiwis.

The kiwi we use does not have any contact with visitors. We show him off in a specially made plexiglass box so that viewers can get a good look at him. He has been trained to do the program by getting earthworms as a reward, which we are now using to train our chick Manaia.

Yes. They are nocturnal flightless birds that feed on the ground. They are omnivores, but 80 percent of their food is made up of various insects and they love worms, which, of course, live underground. It is also interesting to note that they are the only bird in the world with nostrils located at the end of their bills, and they have the second-best sense of smell of any bird. Most birds do not have a very developed sense of smell as they do not look for food or predators that way.

Kiwis are "hard-wired," so to speak. They know what they are supposed to do and be. This is what makes it easy to "hand rear" the chicks and release them back to the wild. They do not imprint, like most birds. They are fairly solitary until they set up their home areas and look for a mate. When Manaia finally matures and receives a mate, he will know what to do.

Most species of kiwi live only with their mate. They do not have any interactions with other bird species to speak of. Being nocturnal really reduces encounters with other bird species.

In the wild (even before the introduced animal predators) kiwi eggs could be eaten by some native fauna. The research conducted in New Zealand regarding the conservation program Operation Nest Egg has not been shown to have a detrimental effect on the species. Since North Island brown kiwis do not rear their young, removing their eggs does not affect the parents, especially the mother, who does not incubate the egg.

When we clean each day, it's just easier to move the box to an area that's already clean. Also, I think it's stimulating for him to have a slightly different environment. Kiwis in the wild have several different burrows that they will use, unless a male is incubating an egg.

It looks like, according to DNA analysis, the closest relative is the cassowary.

Kiwi stay the same color throughout their lifetime. Different species of kiwi do have variations of color, including the great spotted kiwi, which looks like it has whitish spots over its body.

There are many steps being taken to save kiwis. The best-known program is Operation Nest Egg, which removes eggs and chicks from the wild, rears them in captivity, and releases them back into the wild after they are a certain age and weight. This improves their chances for survival as they will be large enough that the stoats and cats will probably not eat them. There are many areas in New Zealand that are maintained by trapping and poisoning and also by enclosing large areas to keep out predators. There are also smaller islands that have been swept free of predators, and kiwis (among other species) are introduced and maintained.

New Zealand is very old set of islands, about 90 million years old, and mammals did not exist on the islands (except for three species of bats) until people arrived, about 1,000 years ago. So kiwi took the place of a burrowing type of mammal. Kiwis have been around for about 39 million years.

Thanks for you concern. Manaia and other kiwis spend a lot of their time marking and patrolling their territory. He cannot be housed with our other kiwi as he is still small and very young. In the wild these young birds are by themselves until they are old enough to start looking for a mate and establish their own territory. North Island brown kiwis are not social birds, they do not live in flocks. When they are old enough (and lucky enough) they find a mate.

The Maori named the bird either for the sound it makes (which sounds like "kiwi"). You can hear kiwi vocalizations on the Bank of New Zealand Save the Kiwi website. The odds of seeing kiwis in the wild are slim. If you go to Stewart Island there is a guide who has permission to lead small groups out to a beach where a species of kiwi comes out to feed on the beach.

It all has to do with New Zealand's very interesting natural history. The islands go back about 90 million years. The only mammals that occurred there naturally were three species of bats until people came (roughly about 1,000 years ago). There were no real predators of kiwi so they evolved a much easier way to deal with their offspring: they just send them out into the world. There is a species of kiwi that (according to ongoing research) seems to form family groups, with the prior offspring staying in the parental area for several years. It appears that they might even help rear young but it is unclear at this point. The more we do research on different kiwi species, the more we come to understand they can be very different.

Please see the information above about New Zealand's history. When people came to New Zealand, about 1,000 years ago, they introduced animals against which kiwis have no natural defenses.

They drink from ponds, streams, and other sources of water is in their area.

Depends on which species you are asking about. One species, the rowi, is in the range of 300-400 birds but that number is actually growing (the only one on the rise). The North Island brown kiwi population is about 24,000, down from 60,000 just 20 years ago. This species is losing about four to six percent of its population each year.

In zoos, there is a higher chance of the embryo dying if left with the parents full term. Kiwis have about a 50-percent egg failure rate in the wild—they just didn't have to be that good at it with the natural lack of predators (which were introduced when humans brought dogs, cats, and stoats to New Zealand). By pulling the egg after day 30 or so we can artificially increase our chances for the chick to hatch.

As for your second question, brown kiwis do not raise their chicks; the chicks are left to fend for themselves. They do not imprint, so there is no harm done when they are "raised" by humans.

He is usually already asleep in his box when I come in at 6 a.m., so he just sleeps away while I clean.

We move it around for the same reason we move around the other objects in his enclosure: to make life more interesting. It motivates him to find out where his food and water are.

I have not seen Manaia doing this, but kiwis do dig around the soil/mulch normally, looking for insects. Kiwis do not build, but do dig burrows for sleeping and nesting areas.

Kiwi belong to a very ancient group of birds. They date back about 39 million years. I am not a geneticist so I don’t think I can really answer this question fully. But what I will do is pose this to our genetics team and get a clearer answer for you, so stay tuned. Kiwis definitely have some non-bird like features. They have two functional ovaries, and their temperature is more like that of a mammal, lower than other birds. Their eye sockets are like a mammal's, divided by large nasal cavities. Their sense of smell is second only to the condor (and not by much), and their nostrils are located at the tip of their bill. Most birds have an underdeveloped sense of smell. Kiwis truly are an "honorary mammal".

More from a Zoo geneticist: The chromosomes of kiwis and other "ratites" (ostrich, rhea, cassowary) are unique because the two sex chromosomes are indistinguishable in size. Birds have Z and W sex chromosomes that are equivalent to the mammalian X and Y chromosomes (see note below*). Usually the two different sex chromosomes can be distinguished readily under a microscope because they differ greatly in size and shape. However, in kiwis and other ratites, the two chromosomes appear identical because they are exactly the same size. Therefore, scientists have had trouble locating DNA "markers" that are unique to either the Z or W chromosome in birds like kiwis.

*As an interesting side note, bird sex chromosomes act in the opposite way of mammals: in birds the females are ZW (heterogametic) and males are ZZ (homogametic), while in mammals females are XX and males are XY.

Probably the most "primitive" characteristic of the kiwi is its simple hair-like feathers, which are thought to be similar to feathers found on several avian-like dinosaur fossils. Kiwis also have a number of physical and behavioral traits that are considered mammal-like. However, these are not "primitive" traits in an evolutionary sense. Instead, these traits probably result from the kiwi fulfilling a traditionally mammalian role on New Zealand as a flightless, ground-dwelling, burrowing bird. Since mammals were historically missing from New Zealand, it is thought that the kiwi evolved "mammalian-like" traits due to its mammalian-like ecological role. For example, kiwis have a sharp sense of smell and poor eyesight, both of which are common mammal traits and help kiwis find food in the ground. Kiwis also have functionally alternating ovaries like mammals (birds typically only have one functioning ovary). The reasons for this discrepancy in kiwis are unknown.

The simple answer is no. Why? For one thing, most exotic animals and birds do not make good pets; they are not domesticated. Kiwis do not imprint like other animal and birds that are "hand-reared" (by humans), so they never become even slightly social, like some hand-reared parrots that imprint. Also, they are a protected species just like our migratory birds here in the U.S.

We are not really sure of this yet, I know of some kiwis that are in their 30s, including a female that hatched in 1971 (in New Zealand) and still produces two chicks every year. Time will give us a better idea about this. The National Zoo is home to the first kiwi to hatch outside of New Zealand (in 1975).

No other species of kiwi has ever been kept in captivity outside of New Zealand.

No, once these birds reach maturity and especially once they become paired up, they revert back to their natural attitude, which is aggressive. This is actually a very positive aspect. When any animal is released into the wild, you don’t want it to be accustomed to humans. Manaia will probably remain "nice" for a kiwi for a while yet, but already I have noticed that he has become a little more independent.

The quick answer to that is no. We want him on a balanced diet. In New Zealand, kiwis get a huge variety of food items; here our live food would be limited. When he gets older (maybe around six months), I will offer him some worms.

Yes. They are very small and basically useless.

We are not really sure of the answer to this yet, but we believe kiwis can live up to 60 years. The lifespan is probably the same in zoos.

When our kiwi hatched, it weighed 274 grams and was about five inches tall (at the most).

The adult average weight for a male North Island brown kiwi ranges from 1.5 to 2 kilograms (3.3 to 4.4 pounds). Females' weight ranges from about 1.8 to 2.6 kilograms (4 to 5.7 pounds). Adult kiwis stand at about the height of a chicken, about 400 millimeters (15.7 inches).

There is a program in New Zealand called Operation Nest Egg. It's been running since 1994. In the program, eggs are collected from the wild and the chicks are reared up to a certain size and released into different safe areas. This has been a tremendous boost to the population. Every year the program has expanded and is now including different species of kiwi throughout New Zealand (there are five kiwi species). It has also been used as the startup program for different New Zealand bird species. New Zealand is very advanced in its bird conservation programs, world leaders, in fact. It takes conservation issues very seriously. You can go to the Kiwi Recovery website, sponsored by the Bank of New Zealand, which will tell you all about it.

He will probably continue to grow in spurts (sort of like children) but generally will keep growing until he is 2 to 2.5 years old. Females reach a weight of about 5.7 pounds; adult males may be as much as 4.4 pounds.

Kiwis are found only in New Zealand and have been around for about 39 million years, one of the oldest bird species that is still around. The only species in collections outside of New Zealand is the North Island brown kiwi, which is endangered. There are about 24,000 of these birds left in the wild. The population is losing about four to five percent a year.

The fruit kiwi is native to China and not a native fruit to New Zealand. I suppose if someone offered it to a bird, it might be eaten, but I don’t know of anyone who offers that fruit to kiwis in collections.

It's an infra-red camera; no lighting is involved. So keep watching and enjoy!

No, they are not friendly birds. When the birds reach adulthood they become extremely aggressive. The young birds are not so bad, so at this point the chick is quite "nice."

We don’t that the final answer on kiwi lifespan yet, but New Zealand experts estimate that 60 years would not be abnormal in the wild (if they don’t get eaten). The San Diego Zoo and the Columbus Zoo, in Ohio, are the other two U.S. zoos with kiwis. No zoos in South America, Central America, or Canada have kiwis. A couple of zoos in Germany and one in Japan have kiwis. Regarding your third question, there are several conservation programs in place in New Zealand. Operation Nest Egg is the most well known, and gets support from both government and the private sectors. You can get detailed information on various programs at this website. New Zealanders take bird conservation very seriously and are world leaders in conservation programs.

Yes, I also added some rocks, grasses, and pieces of driftwood to make it more interesting.

He definitely is out more. Unfortunately the camera had to be placed in a certain area for electricity. That’s one reason we are putting his food farther in the enclosure. I am not sure why he finds that area so attractive, nothing really there but mulch. When I watched him the last few nights (around 9 p.m. to midnight EST) I saw him at both his food bowls and the water bowl. Yes, kiwis do seem to form long-term pair bonds.

Yes, there are two males living there presently—Toru (who hatched here in 1975) and Baxter (who hatched at the San Diego Zoo). Its hard to predict exactly when is a good time to see them. They do not like noise and they can hear the crowds, or if people bang on the glass that will shut them down for a time. Mornings and later in the afternoon are better times. We do bring Baxter out for an education talk called Meet a Kiwi at 11 a.m. on Mondays, Wednesdays, and Fridays. Try to look around the plants and pool area; if they are sleeping they will look like brown hairy rocks. If you find a keeper, feel free to ask if he or she has a moment to spot the kiwis for you.

Their feathers are sort of like ostrich feathers. They have a very dense coat, about an inch thick, to keep them warm and dry. Feels sort of like a mane or tail of a horse.

Toru, the first kiwi to hatch outside of its native New Zealand, at the Zoo in 1975, is male and is still going strong. That makes him 30 years old, about middle age. I am working out the genealogy right now on overseas captive kiwi so I can't be sure about that yet. No, the Daylight Saving time would not affect him, but it was a big move to a different area with different lighting during the day and different sounds. But he seems to be coming out more and his weight is going up.

Yes, you are right. The first egg was small and infertile, not unusual for this species (at least in captivity). The second egg was the one that hatched.

No, North Island brown kiwi chicks do not receive any parental care from their parents. They will stay in the parents' area from eight weeks to six months old and then move on.

The first kiwi that hatched outside of New Zealand was here in 1975. The National Zoo has a record of a kiwi being here in the early 1900s.

That depends. North Island brown kiwis can lay up to five eggs in a season. Sometimes they will lay only two eggs in a season. It can really vary.

In zoos, there is a higher chance of the embryo dying if left with the parents full term. As for your second question, brown kiwis do not raise their chicks; the chicks are left to fend for themselves. They do not imprint so there is no harm done when they are "raised" by humans. They are "hard wired" so to speak.