Weka
Encyclopedia
The Weka or woodhen is a flightless bird
species of the rail
family
. It is endemic
to New Zealand
, where four subspecies
are recognized. Weka are sturdy brown birds, about the size of a chicken
. As omnivore
s, they feed mainly on invertebrate
s and fruit
. Weka usually lay egg
s between August and January; both sexes help to incubate.
is about 5 cm (2 in) long, stout and tapered, and used as a weapon. The pointed tail is near-constantly being flicked, a sign of unease characteristic of the rail family
. Weka have sturdy legs and reduced wings.
The common name Weka is a Māori
word. The species was named Rallus australis by Anders Erikson Sparrman in 1789. Sparrman published the information in Museum Carlsonianum, four fascicules based on specimens collected while voyaging with Captain James Cook
between 1772 and 1775. Australis is Latin for "southern". Johann Georg Wagler
's suggestion of the Ocydromus genus in 1830 to describe each Weka as a species was generally adopted. However, Weka were later decided as a single species in the Gallirallus
genus with four subspecies.
The Buff Weka (Gallirallus australis hectori) formerly inhabited the eastern districts of the South Island
but is now confined to Chatham Island and Pitt Island to which it was introduced in the early 1900s, and where they are widely hunted and eaten, being considered 'introduced'. Reintroduction into Canterbury
has been unsuccessful so far. It has a lighter overall colouring than the other subspecies. The North Island Weka (Gallirallus australis greyi) is represented by original populations in Northland and Poverty Bay
, and by liberations elsewhere from that stock. This subspecies differs in its greyer underparts, and brown rather than reddish coloured legs.
The Western Weka (Gallirallus australis australis) is found mainly in the northern and western regions of the South Island
from Nelson
to Fiordland
. Distinguished by dark red-brown and black streaking on the breast, the Western Weka has two distinct colour phases, that of the southernmost range showing a greater degree of black. The Stewart Island Weka (Gallirallus australis scotti) is smaller than the other subspecies and, like the Western Weka, has two colour phases; a chestnut form - similar to the chestnut-phase Western Weka - and a black phase which is not as dark as the black Western Weka. The population is confined to Stewart Island/Rakiura
and outliers, and to Kapiti Island
to which it was introduced.
s, sub-alpine grassland, sand dunes, rocky shore
s and modified semi-urban environments. They are omnivorous, with a diet comprising 30% animal foods and 70% plant foods. Animal foods include earthworm
s, larva
e, beetle
s, weta
, ant
s, grass grub
s, slug
s, snail
s, insect
egg
s, slater
s, frog
s, spider
s, rat
s, mice
, and small birds. Plant foods include leaves
, grass
, berries
and seeds
. Weka are important in the bush as seed dispersers, distributing seeds too large for smaller berry-eating birds. Where the Weka is relatively common, their furtive curiosity leads them to search around houses and camps for food scraps, or anything unfamiliar and transportable.
s are made on the ground under the cover of thick vegetation, and built by making grass
(or similar material) into a bowl to hold about four egg
s. On average, female Weka lay three creamy or pinkish eggs blotched with brown and mauve. Both sexes incubate. The chicks hatch after a month, and are fed by both parents until fully grown between six and ten weeks.
. The Department of Conservation's Weka recovery plan, approved in 1999, aims to improve the conservation status of threatened Weka, clarify the status of data deficient Weka, maintain the non-threatened status of other Weka, and eventually restore all Weka to their traditional ranges as a significant component of the ecosystems.
Weka are problematic in conservation; some subspecies are threatened, but have been a problem to other threatened wildlife on offshore islands, especially when introduced to an island that they would not naturally inhabit. Weka are unable to withstand the current pressures faced in both the North Island
and South Island
. However, they can be very productive in good conditions and high food availability. Year-round breeding has been recorded at several sites with up to 14 young produced in a year. Weka populations can persist in highly modified habitats, but they have disappeared from huge areas of their former range, suggesting that they can adapt to a wide range of conditions but are particularly vulnerable to threats.
by ferret
s, cats and dogs are a threat to adult Weka; stoat
s, ferrets are a threat to chicks; stoats and rat
s are a threat to eggs. It faces competition with introduced species for fruits and invertebrates, and suffers from the impact browsers have on forest composition and regeneration. Habitat depletion is caused by the modification and degradation of forests and wetlands. Disease
s and parasites have been associated with population declines, although little is known. Drought
has been implicated in the disappearance of Weka from some areas. In some regions, motor vehicle
s cause a significant amount of roadkill
death. Pest control operations sometimes kill Weka, as they have ground foraging habits vulnerable to poison baits, and traps are laid in a way that Weka can reach. Genetic diversity
can be lost during the transmission of genes through generations, affecting isolated populations.
who admire their curiosity and feisty, bold personality, traits which have led to them being relatively easy to catch. Weka were used by the Māori as a source of food, perfume
, oil
to treat inflammation
s, feather
s in clothing and lures to catch dogs. Early European explorers and settlers frequently encountered and utilised Weka; they were called "bush hens".
Tales of Weka stealing shiny items and bags of sugar are part of New Zealand folklore.
Flightless bird
Flightless birds are birds which lack the ability to fly, relying instead on their ability to run or swim. They are thought to have evolved from flying ancestors. There are about forty species in existence today, the best known being the ostrich, emu, cassowary, rhea, kiwi, and penguin...
species of the rail
Rallidae
The rails, or Rallidae, are a large cosmopolitan family of small to medium-sized birds. The family exhibits considerable diversity and the family also includes the crakes, coots, and gallinules...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
. It is endemic
Endemism in birds
An endemic bird area is a region of the world that contains two or more restricted-range species, while a "secondary area" contains one or more restricted-range species. Both terms were devised by Birdlife International....
to New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, where four subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
are recognized. Weka are sturdy brown birds, about the size of a chicken
Chicken
The chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...
. As omnivore
Omnivore
Omnivores are species that eat both plants and animals as their primary food source...
s, they feed mainly on invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s and fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
. Weka usually lay egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s between August and January; both sexes help to incubate.
Description
Wekas are large rails. They are predominantly rich brown mottled with black and grey; the brown shade varies from pale to dark depending on subspecies. The male is the larger sex at 50–60 cm (19.7–23.6 in) in length and 532–1605 g (1.2–3.5 lb) in weight. Females measure 46–50 cm (18.1–19.7 in) in length and weigh 350–1035 g (0.771617917647072–2.3 lb). The reduced wingspan range from 50 to 60 cm (19.7 to 23.6 in). The relatively large, reddish-brown beakBeak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
is about 5 cm (2 in) long, stout and tapered, and used as a weapon. The pointed tail is near-constantly being flicked, a sign of unease characteristic of the rail family
Rallidae
The rails, or Rallidae, are a large cosmopolitan family of small to medium-sized birds. The family exhibits considerable diversity and the family also includes the crakes, coots, and gallinules...
. Weka have sturdy legs and reduced wings.
Taxonomy and distribution
Maori language
Māori or te reo Māori , commonly te reo , is the language of the indigenous population of New Zealand, the Māori. It has the status of an official language in New Zealand...
word. The species was named Rallus australis by Anders Erikson Sparrman in 1789. Sparrman published the information in Museum Carlsonianum, four fascicules based on specimens collected while voyaging with Captain James Cook
James Cook
Captain James Cook, FRS, RN was a British explorer, navigator and cartographer who ultimately rose to the rank of captain in the Royal Navy...
between 1772 and 1775. Australis is Latin for "southern". Johann Georg Wagler
Johann Georg Wagler
Johann Georg Wagler was a German herpetologist.Wagler was assistant to Johann Baptist von Spix, and became Director of the Zoological Museum at the University of Munich after Spix's death in 1826...
's suggestion of the Ocydromus genus in 1830 to describe each Weka as a species was generally adopted. However, Weka were later decided as a single species in the Gallirallus
Gallirallus
Gallirallus is a genus that contains about a dozen living species of rails that live in the Australasian-Pacific region. Many of these, including the most well-known one - the bold and inquisitive weka of New Zealand - are flightless or nearly so; others, such as the Buff-banded Rail, can go for...
genus with four subspecies.
The Buff Weka (Gallirallus australis hectori) formerly inhabited the eastern districts of the South Island
South Island
The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...
but is now confined to Chatham Island and Pitt Island to which it was introduced in the early 1900s, and where they are widely hunted and eaten, being considered 'introduced'. Reintroduction into Canterbury
Canterbury
Canterbury is a historic English cathedral city, which lies at the heart of the City of Canterbury, a district of Kent in South East England. It lies on the River Stour....
has been unsuccessful so far. It has a lighter overall colouring than the other subspecies. The North Island Weka (Gallirallus australis greyi) is represented by original populations in Northland and Poverty Bay
Poverty Bay
Poverty Bay is the largest of several small bays on the east coast of New Zealand's North Island to the north of Hawkes Bay. It stretches for 10 kilometres from Young Nick's Head in the southwest to Tuaheni Point in the northeast. The city of Gisborne is located on the northern shore of the bay...
, and by liberations elsewhere from that stock. This subspecies differs in its greyer underparts, and brown rather than reddish coloured legs.
The Western Weka (Gallirallus australis australis) is found mainly in the northern and western regions of the South Island
South Island
The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...
from Nelson
Nelson, New Zealand
Nelson is a city on the eastern shores of Tasman Bay, and is the economic and cultural centre of the Nelson-Tasman region. Established in 1841, it is the second oldest settled city in New Zealand and the oldest in the South Island....
to Fiordland
Fiordland
Fiordland is a geographic region of New Zealand that is situated on the south-western corner of the South Island, comprising the western-most third of Southland. Most of Fiordland is dominated by the steep sides of the snow-capped Southern Alps, deep lakes and its ocean-flooded, steep western valleys...
. Distinguished by dark red-brown and black streaking on the breast, the Western Weka has two distinct colour phases, that of the southernmost range showing a greater degree of black. The Stewart Island Weka (Gallirallus australis scotti) is smaller than the other subspecies and, like the Western Weka, has two colour phases; a chestnut form - similar to the chestnut-phase Western Weka - and a black phase which is not as dark as the black Western Weka. The population is confined to Stewart Island/Rakiura
Stewart Island/Rakiura
Stewart Island/Rakiura is the third-largest island of New Zealand. It lies south of the South Island, across Foveaux Strait. Its permanent population is slightly over 400 people, most of whom live in the settlement of Oban.- History and naming :...
and outliers, and to Kapiti Island
Kapiti Island
-External links:* , Department of Conservation* * , Nature Coast Enterprise *...
to which it was introduced.
Habitat and diet
Weka occupy areas such as forestForest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s, sub-alpine grassland, sand dunes, rocky shore
Rocky shore
A rocky shore is an intertidal area of seacoasts where solid rock predominates. Rocky shores are biologically rich environments, and make the ideal natural laboratory for studying intertidal ecology and other biological processes...
s and modified semi-urban environments. They are omnivorous, with a diet comprising 30% animal foods and 70% plant foods. Animal foods include earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...
s, larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e, beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s, weta
Weta
Weta is the name given to about 70 insect species endemic to New Zealand. There are many similar species around the world, though most are in the southern hemisphere. The name comes from the Māori word 'wētā' and is the same in the plural...
, ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s, grass grub
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
s, slug
Slug
Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...
s, snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s, insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s, slater
Woodlouse
A woodlouse is a crustacean with a rigid, segmented, long exoskeleton and fourteen jointed limbs...
s, frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s, spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s, rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s, mice
MICE
-Fiction:*Mice , alien species in The Hitchhiker's Guide to the Galaxy*The Mice -Acronyms:* "Meetings, Incentives, Conferencing, Exhibitions", facilities terminology for events...
, and small birds. Plant foods include leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
, grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
, berries
Berry
The botanical definition of a berry is a fleshy fruit produced from a single ovary. Grapes are an example. The berry is the most common type of fleshy fruit in which the entire ovary wall ripens into an edible pericarp. They may have one or more carpels with a thin covering and fleshy interiors....
and seeds
SEEDS
SEEDS is a voluntary organisation registered under the Societies Act of India....
. Weka are important in the bush as seed dispersers, distributing seeds too large for smaller berry-eating birds. Where the Weka is relatively common, their furtive curiosity leads them to search around houses and camps for food scraps, or anything unfamiliar and transportable.
Breeding and nesting
The breeding season varies, but when food is plentiful, Weka can raise up to four broods throughout the whole year. NestBird nest
A bird nest is the spot in which a bird lays and incubates its eggs and raises its young. Although the term popularly refers to a specific structure made by the bird itself—such as the grassy cup nest of the American Robin or Eurasian Blackbird, or the elaborately woven hanging nest of the...
s are made on the ground under the cover of thick vegetation, and built by making grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
(or similar material) into a bowl to hold about four egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s. On average, female Weka lay three creamy or pinkish eggs blotched with brown and mauve. Both sexes incubate. The chicks hatch after a month, and are fed by both parents until fully grown between six and ten weeks.
Conservation status
Weka are classed as a vulnerable speciesVulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
. The Department of Conservation's Weka recovery plan, approved in 1999, aims to improve the conservation status of threatened Weka, clarify the status of data deficient Weka, maintain the non-threatened status of other Weka, and eventually restore all Weka to their traditional ranges as a significant component of the ecosystems.
Weka are problematic in conservation; some subspecies are threatened, but have been a problem to other threatened wildlife on offshore islands, especially when introduced to an island that they would not naturally inhabit. Weka are unable to withstand the current pressures faced in both the North Island
North Island
The North Island is one of the two main islands of New Zealand, separated from the much less populous South Island by Cook Strait. The island is in area, making it the world's 14th-largest island...
and South Island
South Island
The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...
. However, they can be very productive in good conditions and high food availability. Year-round breeding has been recorded at several sites with up to 14 young produced in a year. Weka populations can persist in highly modified habitats, but they have disappeared from huge areas of their former range, suggesting that they can adapt to a wide range of conditions but are particularly vulnerable to threats.
Threats
The Department of Conservation identifies eight main threats to Weka. PredationPredation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
by ferret
Ferret
The ferret is a domesticated mammal of the type Mustela putorius furo. Ferrets are sexually dimorphic predators with males being substantially larger than females. They typically have brown, black, white, or mixed fur...
s, cats and dogs are a threat to adult Weka; stoat
Stoat
The stoat , also known as the ermine or short-tailed weasel, is a species of Mustelid native to Eurasia and North America, distinguished from the least weasel by its larger size and longer tail with a prominent black tip...
s, ferrets are a threat to chicks; stoats and rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s are a threat to eggs. It faces competition with introduced species for fruits and invertebrates, and suffers from the impact browsers have on forest composition and regeneration. Habitat depletion is caused by the modification and degradation of forests and wetlands. Disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
s and parasites have been associated with population declines, although little is known. Drought
Drought
A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...
has been implicated in the disappearance of Weka from some areas. In some regions, motor vehicle
Motor vehicle
A motor vehicle or road vehicle is a self-propelled wheeled vehicle that does not operate on rails, such as trains or trolleys. The vehicle propulsion is provided by an engine or motor, usually by an internal combustion engine, or an electric motor, or some combination of the two, such as hybrid...
s cause a significant amount of roadkill
Roadkill
Roadkill is an animal or animals that have been struck and killed by motor vehicles. In the United States of America, removal and disposal of animals struck by motor vehicles is usually the responsibility of the state's state trooper association or department of transportation.-History:During the...
death. Pest control operations sometimes kill Weka, as they have ground foraging habits vulnerable to poison baits, and traps are laid in a way that Weka can reach. Genetic diversity
Genetic diversity
Genetic diversity, the level of biodiversity, refers to the total number of genetic characteristics in the genetic makeup of a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary....
can be lost during the transmission of genes through generations, affecting isolated populations.
Human interaction and folklore
Weka are significant to some Māori iwiIwi
In New Zealand society, iwi form the largest everyday social units in Māori culture. The word iwi means "'peoples' or 'nations'. In "the work of European writers which treat iwi and hapū as parts of a hierarchical structure", it has been used to mean "tribe" , or confederation of tribes,...
who admire their curiosity and feisty, bold personality, traits which have led to them being relatively easy to catch. Weka were used by the Māori as a source of food, perfume
Perfume
Perfume is a mixture of fragrant essential oils and/or aroma compounds, fixatives, and solvents used to give the human body, animals, objects, and living spaces "a pleasant scent"...
, oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
to treat inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
s, feather
Feather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...
s in clothing and lures to catch dogs. Early European explorers and settlers frequently encountered and utilised Weka; they were called "bush hens".
Tales of Weka stealing shiny items and bags of sugar are part of New Zealand folklore.