Kereru
Encyclopedia
The New Zealand Pigeon or kererū (Hemiphaga novaeseelandiae) is a bird
endemic
to New Zealand
. Māori
call it Kererū in most of the country but kūkupa and kūkū in some parts of the North Island, particularly in Northland. New Zealand pigeons are commonly called wood pigeons but are not the same as the Wood Pigeon
(Columba palumbus), which is a member of a different genus.
The New Zealand Pigeon belongs to the family Columbidae, and the subfamily Treroninae
, which is found throughout Southeast Asia
, Malaya
, Africa
and New Zealand. The members of this subfamily feed largely on fruit
s, mainly drupe
s. New Zealand Pigeons are members of the pigeon
genus Hemiphaga (Bonaparte
, 1854), which is endemic to the New Zealand archipelago and Norfolk Island
. However recently a Hemiphaga bone was found on Raoul Island
. The Parea
or Chatham Island Pigeon (Hemiphaga chathamensis) is traditionally considered a subspecies
of the Kererū, but is here treated as a separate species
.
The New Zealand Pigeon is a large, 550 –, arboreal fruit-pigeon found in forests from Northland to Stewart Island/Rakiura
, ranging in habitats from coastal to montane
. The general morphology
is that of a typical pigeon, in that it has a relatively small head, a straight soft-based bill and loosely attached feathers. It also displays typical pigeon behaviour, which includes drinking by suction, a wing-threat display, hitting with the wing when threatened, a diving display flight, a 'bowing' display, ritualised preening and 'billing' during courtship. New Zealand Pigeons build flimsy, shallow, twiggy nests and feed crop milk
to hatchlings.
The mainland New Zealand Pigeon grows to some 51 centimetres (20.1 in) in length and 650 grams (22.9 oz) in weight, compared to 55 centimetres (21.7 in) and 800 grams (28.2 oz) for the Chatham Island variant. The head, throat and wings are generally a shiny green-purple colour, but with a bronze tinge to the feathers. The breast is typically white and the bill red with an orange-ish tip. The feet and eyes are red. Juveniles have a similar colouration but are generally paler with dull colours for the beak, eyes and feet and a shorter tail.
The New Zealand Pigeons make occasional soft coo sounds (hence the onomatopoeic names), and their wings make a very distinctive "whooshing" sound as they fly. The bird's flight is also very distinctive. Birds will often ascend slowly before making impressively steep parabolic dives; it is thought that this behaviour is often associated with nesting, or nest failure.
of New Zealand Pigeon; of these, only two survive: H. n. novaseelandiae of mainland New Zealand and H. n. chathamensis of the Chatham Islands
. The other subspecies, Norfolk Island Pigeon
(H. n. spadicea) of Norfolk Island
, is now extinct
. The subspecies differ in their plumage colour and physical morphology.
In 2001, it was proposed that H. n. chathamensis, the Parea
, was distinct enough to be raised to full species
status, H. chathamensis, instead of the traditional subspecies status, H. n. chathamensis. Few authorities outside New Zealand have followed this, with most still considering it a subspecies.
, primarily eating fruits from native trees. They play an important ecological role, as they are the only birds capable of eating the largest native fruits and drupe
s (those with smallest diameter
greater than 1 cm), such as those of the taraire
, and thus spreading the seeds intact. While fruit comprises the major part of their diets, the New Zealand Pigeon also browses on leaves and buds, especially nitrogen rich foliage during breeding.
One of their favourite leaves to eat is from an introduced plant, the common plum tree
. The diet changes seasonally as the availability of fruit changes, and leaves can comprise the major part of the diet at certain times of the year, such as when there is little fruit around.
and Arecaceae
which abound in the essentially subtropical forests of northern New Zealand. They also feed on podocarp species, thought to be relics of the flora of Gondwana
, such as miro
(Prumnopitys ferruginea) and kahikatea
(Dacrycarpus dacrydioides). In the warmer northern half of the North Island, pigeons can nest all year round, except when moulting between March and May, provided enough fruit is available. Further south fewer subtropical tree species grow and in these areas breeding usually occurs between October (early spring) and April (late summer/early autumn), again depending on fruit availability.
New Zealand Pigeons nest in trees, laying a single egg
, in a flimsy nest constructed of a few twigs thrown together. The egg is incubated for 28–29 days and the young bird takes another 30–45 days to fledge. In seasons of plentiful fruit the pigeons can successfully nest up to four times.
The population of the New Zealand Pigeon declined considerably after the arrival of humans in New Zealand, and this trend continues, especially in the North Island
, but they are still relatively common in the west of the South Island
and in coastal Otago
. They are commonly found in native laurel forests
(lowlands in particular), scrub, rural and city gardens and parks.
The introduced Australian common brushtail possum
(Trichosurus vulpecula) and introduced species of rats — mainly the ship or black rat (Rattus rattus) but also the kiore or Polynesian rat (Rattus exulans) and brown rat (Rattus norvegicus) — have significantly reduced the amount of fruit available for pigeons and other native birds and also prey on eggs and nestlings.
Pigeon populations are also under threat from hunting, habitat degradation and poor reproductive success. Pigeons were very numerous until about the 1860s and large flocks used to congregate in fruiting trees to feed. Restrictions on the shooting of pigeons were enacted as early as 1864, with total protection since 1921, although the enforcement against hunting was not consistent. Some Māori protested, claiming a traditional right to hunt the pigeon.
The bird is protected under the Wildlife Act
and there have been prosecutions for shooting it.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
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...
. Māori
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...
call it Kererū in most of the country but kūkupa and kūkū in some parts of the North Island, particularly in Northland. New Zealand pigeons are commonly called wood pigeons but are not the same as the Wood Pigeon
Wood Pigeon
The Wood Pigeon is a species of bird in the Columba genus in the Columbidae family. It is a member of the dove and pigeon family Columbidae.- Distribution :...
(Columba palumbus), which is a member of a different genus.
The New Zealand Pigeon belongs to the family Columbidae, and the subfamily Treroninae
Treroninae
Treroninae is a subfamily of birds from the Columbidae family....
, which is found throughout Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
, Malaya
Malay Peninsula
The Malay Peninsula or Thai-Malay Peninsula is a peninsula in Southeast Asia. The land mass runs approximately north-south and, at its terminus, is the southern-most point of the Asian mainland...
, Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
and New Zealand. The members of this subfamily feed largely on 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,...
s, mainly drupe
Drupe
In botany, a drupe is a fruit in which an outer fleshy part surrounds a shell of hardened endocarp with a seed inside. These fruits develop from a single carpel, and mostly from flowers with superior ovaries...
s. New Zealand Pigeons are members of the pigeon
Dove
Pigeons and doves constitute the bird family Columbidae within the order Columbiformes, which include some 300 species of near passerines. In general terms "dove" and "pigeon" are used somewhat interchangeably...
genus Hemiphaga (Bonaparte
Charles Lucien Bonaparte
Charles Lucien Jules Laurent Bonaparte, 2nd Prince of Canino and Musignano was a French naturalist and ornithologist.-Biography:...
, 1854), which is endemic to the New Zealand archipelago and Norfolk Island
Norfolk Island
Norfolk Island is a small island in the Pacific Ocean located between Australia, New Zealand and New Caledonia. The island is part of the Commonwealth of Australia, but it enjoys a large degree of self-governance...
. However recently a Hemiphaga bone was found on Raoul Island
Raoul Island
Anvil-shaped Raoul Island , the largest and northernmost of the main Kermadec Islands, , has been the source of vigorous volcanic activity during the past several thousand years that was dominated by dacitic explosive eruptions.The area of the island, including fringing islets and rocks...
. The Parea
Parea
The Chatham Pigeon, Chatham Island Pigeon, or Parea is a bird endemic to the Chatham Islands in New Zealand...
or Chatham Island Pigeon (Hemiphaga chathamensis) is traditionally considered a 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...
of the Kererū, but is here treated as a separate species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
.
Description
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 :...
, ranging in habitats from coastal to montane
Montane
In biogeography, montane is the highland area located below the subalpine zone. Montane regions generally have cooler temperatures and often have higher rainfall than the adjacent lowland regions, and are frequently home to distinct communities of plants and animals.The term "montane" means "of the...
. The general morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
is that of a typical pigeon, in that it has a relatively small head, a straight soft-based bill and loosely attached feathers. It also displays typical pigeon behaviour, which includes drinking by suction, a wing-threat display, hitting with the wing when threatened, a diving display flight, a 'bowing' display, ritualised preening and 'billing' during courtship. New Zealand Pigeons build flimsy, shallow, twiggy nests and feed crop milk
Crop milk
Crop milk is a secretion from the lining of the crop of parent birds that is regurgitated to young birds. They are found among all pigeons and doves where they are referred to as pigeon milk...
to hatchlings.
The mainland New Zealand Pigeon grows to some 51 centimetres (20.1 in) in length and 650 grams (22.9 oz) in weight, compared to 55 centimetres (21.7 in) and 800 grams (28.2 oz) for the Chatham Island variant. The head, throat and wings are generally a shiny green-purple colour, but with a bronze tinge to the feathers. The breast is typically white and the bill red with an orange-ish tip. The feet and eyes are red. Juveniles have a similar colouration but are generally paler with dull colours for the beak, eyes and feet and a shorter tail.
The New Zealand Pigeons make occasional soft coo sounds (hence the onomatopoeic names), and their wings make a very distinctive "whooshing" sound as they fly. The bird's flight is also very distinctive. Birds will often ascend slowly before making impressively steep parabolic dives; it is thought that this behaviour is often associated with nesting, or nest failure.
Taxonomy
As generally accepted, there are three subspeciesSubspecies
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...
of New Zealand Pigeon; of these, only two survive: H. n. novaseelandiae of mainland New Zealand and H. n. chathamensis of the Chatham Islands
Chatham Islands
The Chatham Islands are an archipelago and New Zealand territory in the Pacific Ocean consisting of about ten islands within a radius, the largest of which are Chatham Island and Pitt Island. Their name in the indigenous language, Moriori, means Misty Sun...
. The other subspecies, Norfolk Island Pigeon
Norfolk Island Pigeon
The Norfolk Island Pigeon , sometimes called a Wood Quest, was a subspecies of the New Zealand Pigeon that inhabited Norfolk Island. It went extinct around the turn of the 20th century.- Ecology :...
(H. n. spadicea) of Norfolk Island
Norfolk Island
Norfolk Island is a small island in the Pacific Ocean located between Australia, New Zealand and New Caledonia. The island is part of the Commonwealth of Australia, but it enjoys a large degree of self-governance...
, is now extinct
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
. The subspecies differ in their plumage colour and physical morphology.
In 2001, it was proposed that H. n. chathamensis, the Parea
Parea
The Chatham Pigeon, Chatham Island Pigeon, or Parea is a bird endemic to the Chatham Islands in New Zealand...
, was distinct enough to be raised to full species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
status, H. chathamensis, instead of the traditional subspecies status, H. n. chathamensis. Few authorities outside New Zealand have followed this, with most still considering it a subspecies.
Diet
The New Zealand Pigeons are commonly regarded as frugivorousFrugivore
A frugivore is a fruit eater. It can be any type of herbivore or omnivore where fruit is a preferred food type. Because approximately 20% of all mammalian herbivores also eat fruit, frugivory is considered to be common among mammals. Since frugivores eat a lot of fruit they are highly dependent...
, primarily eating fruits from native trees. They play an important ecological role, as they are the only birds capable of eating the largest native fruits and drupe
Drupe
In botany, a drupe is a fruit in which an outer fleshy part surrounds a shell of hardened endocarp with a seed inside. These fruits develop from a single carpel, and mostly from flowers with superior ovaries...
s (those with smallest diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
greater than 1 cm), such as those of the taraire
Taraire
Taraire, Beilschmiedia tarairi, is a tree of the Lauraceae family, endemic to the North Island of New Zealand. It is a common canopy tree in lowland forests north of Auckland, often growing in association with kauri , pōhutukawa , tawapou , and with pūriri on basalt rocks and soils...
, and thus spreading the seeds intact. While fruit comprises the major part of their diets, the New Zealand Pigeon also browses on leaves and buds, especially nitrogen rich foliage during breeding.
One of their favourite leaves to eat is from an introduced plant, the common plum tree
Plum
A plum or gage is a stone fruit tree in the genus Prunus, subgenus Prunus. The subgenus is distinguished from other subgenera in the shoots having a terminal bud and solitary side buds , the flowers in groups of one to five together on short stems, and the fruit having a groove running down one...
. The diet changes seasonally as the availability of fruit changes, and leaves can comprise the major part of the diet at certain times of the year, such as when there is little fruit around.
Breeding
Breeding generally depends on the availability of ripe fruit, which varies seasonally, annually (good years and bad years), and by location. New Zealand Pigeons, like other frugivorous pigeons, feed on many species with tropical affinities, including the LauraceaeLauraceae
The Lauraceae or Laurel family comprises a group of flowering plants included in the order Laurales. The family contains about 55 genera and over 3500, perhaps as many as 4000, species world-wide, mostly from warm or tropical regions, especially Southeast Asia and South America...
and Arecaceae
Arecaceae
Arecaceae or Palmae , are a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates...
which abound in the essentially subtropical forests of northern New Zealand. They also feed on podocarp species, thought to be relics of the flora of Gondwana
Gondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
, such as miro
Prumnopitys ferruginea
Prumnopitys ferruginea is an evergreen coniferous tree which is endemic to New Zealand. Before the genus Prumnopitys was distinguished, it was treated in the related genus Podocarpus as Podocarpus ferrugineus....
(Prumnopitys ferruginea) and kahikatea
Dacrycarpus dacrydioides
Dacrycarpus dacrydioides or kahikatea is a coniferous tree endemic to New Zealand.The tree grows to a height of with a trunk exceeding in diameter, and is buttressed at the base. It is dominant in lowland forest and wetlands throughout the North and South Islands...
(Dacrycarpus dacrydioides). In the warmer northern half of the North Island, pigeons can nest all year round, except when moulting between March and May, provided enough fruit is available. Further south fewer subtropical tree species grow and in these areas breeding usually occurs between October (early spring) and April (late summer/early autumn), again depending on fruit availability.
New Zealand Pigeons nest in trees, laying a single 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...
, in a flimsy nest constructed of a few twigs thrown together. The egg is incubated for 28–29 days and the young bird takes another 30–45 days to fledge. In seasons of plentiful fruit the pigeons can successfully nest up to four times.
Distribution and conservation
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...
, but they are still relatively common in the west 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...
and in coastal Otago
Otago
Otago is a region of New Zealand in the south of the South Island. The region covers an area of approximately making it the country's second largest region. The population of Otago is...
. They are commonly found in native laurel forests
Laurel forest
Laurel forest is a subtropical or mild temperate forest, found in areas with high humidity and relatively stable and mild temperatures. They are characterized by tree species with evergreen, glossy, enlongated leaves, known as laurophyll or lauroide...
(lowlands in particular), scrub, rural and city gardens and parks.
The introduced Australian common brushtail possum
Common Brushtail Possum
The Common Brushtail Possum is a nocturnal, semi-arboreal marsupial of the family Phalangeridae, it is native to Australia, and the largest of the possums.Like most possums, the Common Brushtail is nocturnal...
(Trichosurus vulpecula) and introduced species of rats — mainly the ship or black rat (Rattus rattus) but also the kiore or Polynesian rat (Rattus exulans) and brown rat (Rattus norvegicus) — have significantly reduced the amount of fruit available for pigeons and other native birds and also prey on eggs and nestlings.
Pigeon populations are also under threat from hunting, habitat degradation and poor reproductive success. Pigeons were very numerous until about the 1860s and large flocks used to congregate in fruiting trees to feed. Restrictions on the shooting of pigeons were enacted as early as 1864, with total protection since 1921, although the enforcement against hunting was not consistent. Some Māori protested, claiming a traditional right to hunt the pigeon.
The bird is protected under the Wildlife Act
Wildlife Act 1953
-External links:*...
and there have been prosecutions for shooting it.
Further reading
- Dijkgraaf, Astrid Cora. 2002. Phenology and frugivory of large-fruited species in northern New Zealand and the impacts of introduced mammals. PhD Thesis, School of Biological Sciences. University of Auckland, Auckland.
External links
- Wood pigeon/kereru: New Zealand Native land birds from the Department of Conservation
- The Kereru Discovery Project, a programme for New Zealanders to help arrest the decline of the species through awareness and action in their own gardens.
- Kereru, the New Zealand pigeon, Gallery of New Zealand Birds, New Zealand Birds Ltd