Kiwi

Update of post from November 2, 2013

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Profile

The kiwi is a small, flightless bird living in New Zealand. They belong to a large family of flightless birds called ratites. This family includes ostriches, emus, and rheas.

Unlike these other, larger flightless birds, the kiwi has extremely small wings. They also have no tail. These two things are some of the reasons these birds cannot fly. Large wings (at least compared to the bird’s body size) and a tail are things all birds need to fly. Although they do have small wings, at fist glance it looks like they have none. This is reflected in the genus name Apteryx, which means “wingless.”

Kiwis have a hard life. As if being one of the few birds unable to fly wasn’t enough, they also have terrible eyesight. At night, they can only see about six feet (1.8 m) in front of them, and during the day time that actually decreases to just two feet (0.6 m). These birds are mostly nocturnal, so although they cannot see very far during the day time, they were made with the ability to see a little farther at night. They still cannot see very far, though.

There are five species of kiwi. I have them named below in a list.

  • North Island brown kiwi
  • Great spotted kiwi
  • Little spotted kiwi
  • Okarito brown kiwi (also called the rowi)
  • Tokoeka

Size

The kiwi is probably the smallest of the more common flightless birds such as ostriches, emus, cassowaries, rheas, and penguins. There are some rarer flightless birds that are smaller, though.

These birds are about the same size as chickens, but their specific size varies depending on the species. As its name suggests, the great spotted kiwi is the largest of the kiwi species. For all of the five species listed above, the females are larger – sometimes more than 30% larger  – than the males.

Males of the largest species can be up to 18 inches (46 cm) long and weigh up to 5.3 pounds (2.4 kg). Females are not much longer, reaching at most 20 inches (50 cm), but they are much heavier. They can weigh up to 7.3 pounds (3.3 kg). Some of the species are much smaller, for example, the female little spotted kiwi, which is the smallest species, rarely weighs more than three pounds (1.4 kg)!

Diet and hunting

Kiwis are omnivorous birds, eating a wide variety of plants and animals. As I mentioned earlier, these birds have terrible eyesight, so they were made with another way to find food: smell. Kiwis are different than almost all other birds in that they have nostrils at the end of their beak. These nostrils provide them with the needed sense to find their food.

The main prey of this animal is invertebrates. They use their sense of smell to locate them, and then they dig around in the leaf litter and dirt on the ground until they find them.

In digging around, the kiwi gets dirt in its nostrils, which impedes its sense of smell. In order to get it out, it does what humans would do in that situation. It blows its nose, kind of. Sometimes at night, when these animals are active, a New Zealander may be able to hear a sniffling sound. This is the kiwi blowing dirt out of its nose!

There are many different invertebrates that fall prey to kiwis. These include insects, snails, spiders, worms, and crayfish. Even smaller vertebrates such as frogs and fish may sometimes be this bird’s meal. Some of the plant matter included in the kiwi’s diet is berries and fruit.

Habitat and range

These birds live in many different places throughout New Zealand. The map below shows the range of each of the five species. As you can see, both the okarito brown kiwi and the little spotted kiwi are extremely rare and have a very small range. The northern island brown kiwi has the largest range of all species. It is also one of the only two species that live on the northern island of New Zealand, hence its name

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All species of kiwis typically live in forests, but they also inhabit grasslands and pastures. Some of them will even live on beaches! They also live on mountainsides as far up as 5,000 feet (1500 m) above sea level.

Status and threats

Most of the kiwi species are rather rare. The great spotted kiwi and tokoeka are both classified as “Vulnerable” on the IUCN Redlist, while the same place gives the northern island brown kiwi and the okarito brown kiwi an “Endangered” status. Surprisingly, the little spotted kiwi, which has the smallest range of all the species, is classified as “Near Threatened,” just one step below “Least Concern.”

There are very few, if any, natural predators of the kiwi, but many introduced animals prey on these defenseless birds. New Zealand originally had no predators that would be a threat to a ground-dwelling bird like the kiwi. Since that time, however, cats, dogs, stoats, and possums have been introduced into this country. All of these have become major threats to the kiwi.

Reproduction and young

Kiwi breeding season lasts most of the year, with April and May being pretty much the only months when breeding does not occur. Since these birds live in the southern hemisphere, this is winter.

Kiwis only mate with one other individual during a breeding season, and they will often keep the same mate for a few seasons, or even for life. Most of the time, only one egg is laid per clutch. Sometimes two are laid, but if this happens they are laid a few weeks apart. A single female may lay up to three separate clutches during a single breeding season.

It may be surprising to you that the kiwi only lays one egg at a time, but it has a very good reason. Each egg is about 15% of the female’s body size! This makes it the largest bird egg relative to the mother’s size! The picture below shows how the egg compares to the adult.414px-kiwieggratio-svg

The eggs incubate for between 70 and 80 days. During this time, both the male and female keep the egg warm. When the baby kiwi hatches, it already has all its feathers. Because of this, it is ready to leave the nest in just one week! It may stay in its parents’ territory for another seven years! These birds can live for up to 40 years.

Don’t forget to scroll down and comment your guess about what the next animal is!

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Sources:

Photo credits:

  • Kiwi – Glen Fergus
  • Kiwi range – Public Domain
  • Kiwi egg – Shyamal
  • Mystery animal – Matthias Kabel

One Response

  1. Anonymous
    Anonymous at |

    Wolverine-weasel family. Send check

    Grandpa M

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