Kiwi

About

Kiwis are flightless, nocturnal birds endemic to New Zealand, characterized by their long beaks with nostrils at the tip, strong legs, and shaggy, hair-like plumage. They are the smallest living ratites and are iconic symbols of New Zealand.

Size & lifespan

Length

35-65 cm (14-26 in)

Wingspan

Vestigial wings, not measurable as a functional wingspan (approx. 5 cm/2 in)

Weight

1.3-3.3 kg (2.9-7.3 lbs), with females typically larger than males

Lifespan

25-50 years in the wild

Diet

Omnivore (primarily insectivore/carnivore)

Physical characteristics

Plumage

Dense, shaggy, hair-like feathers, typically brown, grey-brown, or reddish-brown, often streaked or mottled, providing excellent camouflage in forest undergrowth. They lack a tail.

Beak shape

Long, slender, flexible, and slightly downcurved bill, ranging from 9-20 cm (3.5-8 in) depending on the species. Unique among birds, their nostrils are located at the very tip of the bill, providing an exceptional sense of smell.

Eye color

Small, dark eyes, adapted for nocturnal vision but with poor daytime acuity.

Leg color

Strong, stout, and scaly legs, typically greyish-brown to dark brown, with four toes and sharp claws.

Distinguishing features

Flightless, nocturnal, long sensitive whiskers (vibrissae) around the base of the bill, nostrils at the tip of the bill, shaggy plumage, and powerful legs for running and digging.

Juvenile appearance

Juveniles resemble smaller versions of adults, with similar plumage and bill characteristics. They grow rapidly.

Seasonal changes

No significant seasonal plumage changes. Plumage remains consistent year-round.

Sexual dimorphism

Females are generally larger and heavier than males, and their bills are often longer. Otherwise, plumage is similar.

How to identify

1. 1

   Flightlessness and Nocturnal Activity

   Kiwis are unique among New Zealand's native birds for being flightless and primarily active at night. If you encounter a bird-like creature foraging in the dark, it's likely a kiwi.

2. 2

   Long Bill with Nostrils at Tip

   Their most distinctive feature is their exceptionally long, slender bill with nostrils located at the very end, used for sniffing out prey. No other bird has this characteristic.

3. 3

   Shaggy, Hair-like Plumage

   Unlike most birds with distinct feathers, kiwis have a coarse, shaggy, hair-like plumage that provides excellent camouflage in the forest undergrowth.

4. 4

   Strong Legs and Lack of Tail

   They possess powerful, muscular legs for running and digging, and conspicuously lack a visible tail, giving them a distinctive rounded rear profile.

5. 5

   Vocalizations

   Listen for the distinctive, shrill, ascending whistle of the male or the harsher 'kwe-kwe' call of the female, especially at night. These calls are unmistakable.

Habitat & range

Biomes

Temperate forests, subalpine scrub, grasslands, and coastal dunes.

Geographic range

Endemic to New Zealand, found across various regions of the North, South, and Stewart Islands, depending on the species.

Elevation range

Sea level up to approximately 1,200 meters (3,900 ft).

Preferred environments

Dense native forests (podocarp-broadleaf, beech), regenerating scrub, and sometimes exotic pine plantations, particularly areas with deep leaf litter and moist soil for foraging.

Behavior

Activity time

Primarily nocturnal, emerging from their burrows or dens shortly after dusk to forage and returning before dawn. Some individuals may be crepuscular.

Feeding habits

Nocturnal foragers, using their exceptional sense of smell and long bill to probe deep into soil, leaf litter, and rotting logs for invertebrates (earthworms, grubs, insects, spiders). They also consume fallen fruit, fungi, and occasionally small crustaceans or amphibians.

Social behavior

Generally monogamous and territorial, forming long-term pair bonds. They are largely solitary outside of the breeding season, though pairs will share a territory.

Flight pattern

Flightless. They rely on strong legs for movement.

Migration pattern

Resident; non-migratory.

Territoriality

Highly territorial, defending their home ranges (which can be several hectares) with vocalizations and sometimes physical confrontations, especially during the breeding season.

Breeding & reproduction

Breeding season

Typically from June to March, with peak activity between August and November, though it can vary by species and location.

Nesting habits

Nests are usually in burrows dug by the kiwi, hollow logs, or under dense vegetation. The male often prepares the nest site.

Clutch size

Usually 1-2 eggs, rarely 3. Some species may lay multiple clutches in a season.

Egg description

Kiwis lay one of the largest eggs relative to their body size of any bird (up to 20% of the female's body weight). Eggs are typically white or greenish-white, smooth, and oval-shaped.

Incubation period

Approximately 63-92 days, one of the longest incubation periods among birds. The male typically undertakes most, if not all, of the incubation.

Fledging period

Chicks are precocial, hatching fully feathered and able to feed themselves within a few days. They remain dependent on parental protection for several weeks to months, but are not 'fledged' in the typical sense due to flightlessness.

Parental care

Primarily by the male, who incubates the eggs and often cares for the chick for an extended period after hatching. Females may assist in chick rearing but are less involved in incubation.

Where to find

Field tips

1. Go on a Guided Night Walk. The most reliable way to see a kiwi in the wild is to join a guided night walk led by experienced guides who know their territories and behaviors. These are often offered in sanctuaries or specific conservation areas.
2. Listen for Calls. Even if you don't see one, listening for their distinctive calls at night, especially during the breeding season, is a strong indicator of their presence. Use a red-light headlamp to preserve your night vision.
3. Look for Signs. Look for signs of their foraging activity, such as small probe holes in the soil or disturbed leaf litter, particularly in damp, soft ground.
4. Be Patient and Quiet. Kiwis are extremely shy and easily disturbed. If you are in an area where they are known to be present, remain very still and quiet for extended periods.
5. Respect Their Habitat. Never disturb a kiwi or its nest. Keep dogs on a leash in kiwi areas, as dogs are a major threat to kiwi populations.

Quick facts

Status:

Endemic to New Zealand

Flight:

Flightless

Activity:

Nocturnal

Sense of Smell:

Highly developed, nostrils at bill tip

Egg Size:

Largest egg relative to body size of any bird

Conservation:

All species are threatened, facing significant challenges from introduced predators.

Fun facts

• Kiwis are the only birds in the world with nostrils at the end of their long beaks, giving them an exceptional sense of smell, which they use to locate food underground.
• Despite being birds, kiwis have bone marrow, unlike most birds which have hollow bones for flight. Their bones are heavy and filled with marrow, similar to mammals.
• The kiwi egg is enormous, taking up about 20% of the female's body volume. This is equivalent to a human woman giving birth to a six-year-old child!
• Kiwis have whiskers (vibrissae) around their beak, similar to a cat, which they use to sense their surroundings in the dark.
• There are five recognized species of kiwi, each with distinct geographic ranges and some morphological differences: Brown Kiwi (Apteryx mantelli), Rowi (Apteryx rowi), Tokoeka (Apteryx australis), Little Spotted Kiwi (Apteryx owenii), and Great Spotted Kiwi (Apteryx haastii).
• The term 'kiwi' is not only the name of the bird but also a common nickname for New Zealanders themselves.

Scientific classification

Kingdom

Animalia

Phylum

Chordata

Class

Aves

Order

Apterygiformes

Family

Apterygidae

Genus

Apteryx

Species

Apteryx australis, Apteryx haastii, Apteryx mantelli, Apteryx owenii, Apteryx rowi

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