New Zealand has the second-highest number of introduced bird species of any country. Many became pests, damaging agricultural crops or threatening native birds. In situations where native bird species have declined, some introduced birds play a valuable role in pollinating flowers or dispersing native plant seeds.
One hundred and thirty bird species were brought to New Zealand. A few were kept as caged or domestic birds, but most were deliberately set free to live in the wild.
Forty-one species successfully established wild populations. They included 16 passerines (perching or song birds), three pigeons and an owl – nearly all from Europe. From Australia there was the magpie, the kookaburra and three species of parrot. There are also 16 introduced waterfowl and game birds.
Some species were introduced several times before becoming established, while others were ultimately unsuccessful.
For successful establishment, the habitat and climate had to be suitable, and the birds adaptable. Most successes were in land cleared for farming, which was similar to the British countryside from which many species came.
Some, such as the house sparrow, bred prolifically and quickly reached high numbers. Others, such as the cirl bunting, remain rare.
The many species that were introduced but failed to become established include the English robin, the nightingale, the emu and the Solomons cassowary.
To settlers from Great Britain, familiar birds were a sentimental reminder of ‘home’. They missed the well-known tunes of British songbirds, especially since land cleared for farming was unsuitable habitat for most native species.
In the 1860s armyworm caterpillars reached such great numbers that trains sometimes came to a standstill, wheels spinning, because the tracks were made greasy by their crushed bodies. In one account from Rangitīkei, a train was brought to a halt by caterpillars rushing across the rails to reach a nearby field of oats. While the crew cleaned and sanded the rails, the stationary engine and carriages became covered, inside and out, with thousands of caterpillars.
By the early 1850s crop-damaging moths, caterpillars, beetles and grasshoppers had built up in huge numbers, due to the expansion of agriculture and horticulture. One Hawke’s Bay farmer resorted to driving his sheep across infested pasture to trample the coloured carpet of caterpillars.
While some native birds ate insects, they would only forage in farmland if there was bush nearby. As the bush edge was pushed back for agriculture, they had less effect as pest-controllers.
In the hope they would eat agricultural pests, farmers introduced insect-eating birds such as blackbirds, thrushes, starlings, sparrows and magpies.
The first introductions were haphazard, private efforts. From the 1860s regional acclimatisation societies began a more coordinated approach.
Charles Hursthouse was an early advocate of acclimatisation. In 1857 he wrote that rooks, magpies, starlings, sparrows, thrushes and other small birds should be introduced, as well as game birds for hunting. He also proposed the introduction of rabbits, hares and deer – all of which later became serious pests.
Advertisements were placed in English newspapers, offering payment for live birds of the desired species. The species were selected partly on how easily and cheaply ships’ captains could acquire the birds, and their likelihood of surviving the voyage.
Bringing birds to New Zealand on sailing ships was challenging. Voyages from England could take four months, through a range of climates and frequent rough seas. Most birds died en route.
Some acclimatisation societies had criteria for selecting suitable species. For example, as well as eating summer insects, they had to be able to live on other foods – such as fruit, seed or grain – to survive in winter. They had to be non-migratory, so they would stay. And they had to be prolific breeders to have a significant impact on the insect problem.
Hidden in the criteria was a recipe for calamity. Farmers soon discovered that the plagues of insects were replaced by platoons of birds stripping their grain crops and damaging fruit.
From the 1860s acclimatisation societies were at the forefront of introducing birds ranging from small birds, such as sparrows, to large game birds, such as pheasants. But it wasn’t long before some of their own members were complaining that small introduced birds had multiplied so rapidly they were competing with the introduced game birds for food.
Within 15 years of their introduction, there was a coordinated effort to control small European birds by laying out poisoned grain, paying a bounty on eggs and heads, and shooting them. The little owl was introduced in the early 20th century to prey on small introduced birds.
The introduced rock pigeon is a common sight in New Zealand’s towns and cities. It is widespread in both the North and South islands, while the Barbary dove and spotted dove have only small discrete populations. All of these differ in appearance and habits from the native kererū, a much larger fruit pigeon.
Several attempts to establish other pigeon and dove species, including some from Australia, were unsuccessful.
Northern hemisphere rock pigeons (Columba livia) are native to Eurasia. They were brought to New Zealand by early settlers as food, as pets and as racing or messenger pigeons, and they rapidly established large wild populations.
Rock pigeons prefer to roost and nest under overhangs on rock ledges. Their main populations are on coastal sea cliffs, inland gorges and bluffs, and urban sites offering sheltered ledges. They eat grains, legumes such as peas and beans, and sometimes slugs and snails. In cities they scavenge for scraps.
Rock pigeons are about 400 grams in weight and 33 centimetres long. They vary in colour, but most are contrasting shades of grey with glossy green, pink and purple neck feathers.
From 1897 to 1908 Great Barrier Island had a regular pigeon-post service to Auckland, and boasted the world’s first airmail stamps. Initially, the service was one-way, with birds trained to return to a dovecote in Auckland. They went back to the island on the weekly steamer. Up to five messages (including shopping lists) were written on lightweight tissue paper – known as flimsies – and rolled up in an aluminium capsule attached to one leg. The birds usually covered the 92 kilometres in less than two hours, but the speed record was held by a pigeon named Velocity who took just 50 minutes – an average speed of 125 kilometres per hour.
Rock pigeons are used for pigeon racing, and in 2005 New Zealand had over 70 pigeon-racing clubs. A good racing pigeon can travel from Invercargill to Auckland in two days.
The Barbary dove (Streptopelia risoria), originally from central Africa, is small and creamy-coloured, with a black collar around the back of its neck. It is about 140 grams in weight and 28 centimetres long. Found in only a few scattered sites in both main islands – mostly in Auckland, Northland and Hawke’s Bay – the population may be fewer than 100 birds.
The spotted dove (Streptopelia chinensis), or spotted turtle-dove, is a small pinkish-buff dove, with mottled brown wings and back, and a wide black collar speckled with white. It is found only in a few areas in the North Island – Northland, Auckland, the Bay of Plenty and Waikato – mainly in city parks and rural areas. Native to Asia, it was brought to New Zealand as a caged ornamental bird.
Four introduced members of the parrot family have established themselves in New Zealand.
The penetrating screech of a sulphur-crested cockatoo (Cacatua galerita) means it is often heard before it is seen. It is mainly white, but has pale yellow on its crest, under-wing and under-tail feathers.
Sulphur-crested cockatoos are native to parts of Australia and New Guinea. Popular as cage-birds, they were reported in the wild in the Waitākere Ranges in the early 1900s. A hundred years later one population is still centred there, with others in western Waikato, the Turakina–Rangitīkei region, Wellington region and Banks Peninsula.
Occasionally, individual birds are seen further afield – possibly cage escapees, deliberate releases or stragglers from across the Tasman. The total wild population may be fewer than 1,000 birds.
Sulphur-crested cockatoos have a heavy parrot bill, which they use to break open large nuts and seeds. They also eat fruit and berries, bulbous roots, grains, flowers, leaf buds and insect larvae. They roost and nest in bush, but sometimes feed on adjoining farmland so they are often considered a pest.
They usually build their nests high up in tree hollows lined with wood chips, where they lay two or three white eggs.
After the breeding season, cockatoos gather in large flocks. While the main group feeds, a few sentinels perched high up screech to warn of intruders.
The galah (Eolophus roseicapillus), native to Australia, is a pink cockatoo with grey wings. Cage escapees have established a small population centred on Pōnui Island and the nearby Hūnua district – probably fewer than 100 birds.
A parrot native to south-east Australia, the eastern rosella (Platycercus eximius) is about 25 centimetres long and 110 grams in weight – larger than most native New Zealand parakeets.
It has distinctive white cheeks against a red head, face and chest. The underbody is yellow, while its wings and long tail are indigo to green. Eastern rosellas call a ringing ‘kwink kwink’ as they fly, and they also chatter and screech. They have a two-note whistle similar to that of a bellbird.
A shipment of eastern rosellas, and a few crimson rosellas, was released off the Otago heads around 1910, after being denied entry by customs officials. By the early 2000s this Dunedin population was the main South Island group of eastern rosellas.
A separate population was established near Auckland prior to 1920, and another in Wellington around 1960. Eastern rosellas are now widespread in the southern North Island and north of Taupō. They are found mainly in open forest, urban parks, farmland, gardens and orchards.
Crimson rosellas (Platycercus elegans) are popular cage birds, but are probably extinct in the wild in New Zealand. Adults are crimson with blue cheeks, wings and tail, while juveniles are green with red crown, bib and undertail. At about 130 grams and 35 centimetres, they are slightly heavier and longer than the eastern rosella.
The few crimson rosellas released with eastern rosellas near Otago heads became established, but the two species interbred. By the early 2000s only eastern rosellas were seen there.
Cage escapees and their descendants were seen from 1963 in a few leafy parks and suburbs of Wellington, but had apparently died out by the mid-1990s.
The natural range of the little owl (Athene noctua) is Europe, North Africa and Asia. Also known as German owls, they were introduced to Britain in the 1870s. Between 1906 and 1910, about 300 little owls were released in Otago and Canterbury.
In the early 2000s little owls were mainly in the south, east and north of the South Island, and appeared to be spreading in Golden Bay. There were small isolated populations in Westland and Fiordland.
The little owl weighs about 180 grams, slightly heavier than the native morepork (Ninox novaeseelandiae). But its length – about 23 centimetres – is less, because it has a shorter tail.
Little owls were introduced with the aim of reducing the population of small introduced birds, which had become pests on farms. There were concerns that they might damage native bird populations, but their diet turned out to be mainly invertebrates – and occasionally small birds, frogs, lizards and mice. They often walk or run about, feeding on the ground.
Little owls nest in holes in trees, earth banks, rabbit burrows and buildings. They are not strictly nocturnal – they often appear during the day and sometimes sun themselves.
The laughing kookaburra (Dacelo novaeguineae) is a large kingfisher, native to eastern and southern Australia. It is also known as the laughing jackass.
Sir George Grey liberated kookaburras on Kawau Island (near Auckland) in the late 19th century, and this may be the source of the current population. Introductions to other regions were unsuccessful, and their range is small – from Whangārei to the Waitākere Ranges near Auckland. Their total New Zealand population is 500 birds or fewer.
Weighing about 350 grams, the kookaburra is five times as heavy as the native kingfisher and nearly twice as long – 45 centimetres. It has a large square head with a sturdy, pointed bill, and a short neck and legs. The wings are dark brown, and some wing feathers have pale blue tips. The underbody is pale, and there is a dark line through the eye and above the bill.
Their call is an unmistakable loud cackle, often on a slowly ascending then descending scale. Family members form a community and chorus together to defend their territory – usually at dawn and dusk.
Kookaburras are carnivorous. They wait on a high perch for prey, then swoop down to catch it, bashing it against their perch before swallowing it. Common foods include lizards, mice, rats, small birds, aquatic invertebrates, snails and worms. Kookaburras also scavenge human food.
Australian magpies (Gymnorhina tibicen) were introduced in the 1860s and 1870s in Canterbury, Otago, Auckland (Kawau Island), Hawke’s Bay and Wellington. They came from Victoria and Tasmania.
These populations expanded slowly, remaining separate for many years. The original Otago population has disappeared altogether, but magpies are now found over most of the country except the most densely forested regions, such as Fiordland, or the most open country, such as Central Otago.
Magpies reportedly peck away at power-line fittings, sometimes causing lines to short circuit and electrocuting themselves. They have been blamed for starting fires after catching alight and falling into dry vegetation in a ball of flames.
Magpies were introduced to control pasture pests, which is why they were protected until 1951.
Australian magpies have black heads and patchy black-and-white bodies. Their heavy bill is cream with a dark tip. They are about 350 grams in weight and 41 centimetres long.
In the past, there were thought to be two distinct Australian magpie species introduced – white-backed and black-backed. However, they are now considered to be the same species.
Australian magpies eat a mix of plants and animals, including grass and clover seeds, invertebrates (grass grubs, caterpillars, worms, spiders, crickets, snails, flies), and some vertebrates and carrion. They often eat on the ground.
Magpies are reputed to reduce the number of native birds, particularly tūī and kererū. Magpies sometimes raid native birds’ nests for eggs and nestlings. They also mob or attack other birds – harriers in particular – and often kill smaller bird species in acts of territorial defence.
Magpies attack, and occasionally injure, humans and other animals that come within range of their nests during the breeding season.
The call of magpies evokes country life in New Zealand’s dry, eastern regions. In his poem ‘The magpies’, Denis Glover told a story of rural hope and despair against the backdrop of the ever-present magpie cry. His version of their call – ‘quardle oodle ardle wardle doodle’ – has become familiar to many.
Their nests, which they usually build in tall exotic trees, are often made of a mixture of natural and synthetic fibres, such as fencing wire, pieces of string and broken china. They lay three to four eggs, but only one or two chicks are reared. Eggs are usually bluish-green with olive blotches.
Magpies are good mimics, repeating neighbourhood sounds such as barking dogs. They are sometimes kept as pets and taught to mimic words.
A member of the crow family, the rook (Corvus frugilegus) is a large, glossy, purplish-black bird, with a prominent, powerful bill. Whitish patches of skin show around the base of its pale beak. Larger than a magpie, it weighs around 400 grams and is 45 centimetres long.
Rooks announce their presence with a distinctive ‘kaah’, and as they fly they ‘caw’ to keep in contact with each other.
The oldest rook recorded in New Zealand was over 11 years old.
Rooks are native to Europe and Asia. They were introduced successfully to Canterbury and Hawke’s Bay in the 1860s and 1870s. At first they spread slowly, but then expanded rapidly in Hawke’s Bay.
Before long, rooks were cursed for damaging fruit, vegetable, grain and nut crops, especially walnuts. However, for much of the year their diet consists mainly of grubs, worms and other invertebrates. While searching for these they sometimes tear big tufts of grass or seedlings out of the ground.
At one time rooks were accused of attacking and killing lambs – but this was never substantiated.
Rooks generally nest in colonies of 20–150 nests, often in pines and eucalypts. They lay three to five pale greenish-blue eggs with brown blotches, but usually just one or two chicks survive to fledge.
When not breeding, rooks gather in roosts of up to 5,000 birds, known as parishes, and feed in large flocks.
By the 1960s numbers had increased to pest levels. Early control measures – shooting and poisoning – led to displaced birds starting new colonies much further afield, and so actually increasing their range.
The Hawke’s Bay Regional Council’s webpage about rooks says: ‘Rooks are the most destructive introduced birds known to our farming sector, due to the sheer numbers of birds in congregations and that may vary from the Hundreds into the Thousands, these birds are able to strip crops in a matter of days. The flocks of rooks foraging of paddocks for grass grub and worms can leave paddocks looking like mobs of pigs have been through them.
‘During their breeding season rookeries are built near houses or woolsheds and the noise from the rooks is intense and very unwelcome to any household.’ 1
In the 1970s an estimated 35,000 rooks were killed – maybe half the population at the time.
Farmers in the Hawke’s Bay region try to deter rooks with scarecrows, ‘crucified’ dead rooks, machines that make intermittent banging noises, bright flapping objects and ground poisoning.
Regional councils use helicopters to carry a person on a long strop to spray individual nests with a sticky toxin, which birds ingest when preening.
Rooks’ range in the North Island has expanded since the 1980s. In the early 2000s the main population was in Hawke’s Bay and northern Wairarapa.
In the South Island, their range declined over the same period due to effective control. The Canterbury Regional Council aims to eradicate rooks entirely from its area, and numbers fell from over 5,000 in 1993 to 23 birds in 2005. Banks Peninsula, once a rook stronghold, reported none from 2000 to 2006.
Blackbirds (Turdus merula) are native to Europe, north-west Africa and the Middle East.
English settlers introduced blackbirds to New Zealand because their song was a nostalgic reminder of English life. Between 1867 and 1879 blackbirds were liberated on the three main islands, where they multiplied rapidly.
Within 60 years they had spread to the Chatham, subantarctic and Kermadec islands. On mainland New Zealand, blackbirds are now found in most habitats up to 1,500 metres above sea level.
Within 15 years of introduction, blackbirds were becoming a pest because they damaged fruit in orchards and spread the seed of unwanted plants such as elderberry and blackberry. As well as fruit, they also feed on worms, beetles, caterpillars and other invertebrates. Blackbirds sometimes play a useful role spreading the seed of some native plants.
Blackbird males are black with an orange bill and eye-ring, whereas females are dark brown. They are about 25 centimetres long and weigh 90 grams. They have a warbling song and a piercing alarm call.
The oldest blackbird recorded in New Zealand was 15 years old.
Male blackbirds are so intent on defending their territory in the lead-up to nesting that they sometimes attack their own reflection. For several years, each spring residents of a Wellington house found their front door glass covered in blood-smeared beak marks and wing impressions.
Blackbirds return to the same breeding territory each year. The female builds a nest in a fork of a shrub or hedge, which it may reuse in subsequent seasons. They lay three or four blue-green freckled eggs, and raise up to three broods a year.
The song thrush (Turdus philomelos) is closely related to the blackbird, but is slightly smaller and lighter – about 23 centimetres long and 70 grams in weight. Both sexes have a yellow-brown back and wings, and lighter underside with regular rows of tapered brown spots. Their song is a series of repeated notes and trills.
Like the blackbird, thrushes were introduced for sentimental reasons and were soon considered a pest for damaging fruit.
Since their introduction in the 1860s and 1870s, song thrushes have colonised all major island groups of New Zealand. They are common in most habitats, except for intact native forest.
Song thrushes specialise in eating snails, including introduced and native land and marine species. Using a rock, they smash the shell repeatedly until it breaks open. They also eat other invertebrates and fruit.
Nesting habits are similar to blackbirds, but thrushes’ eggs are clear green-blue with black dots.
For farmers, the common starling (Sturnus vulgaris) has been a useful introduction. It helps control unwanted insects, including ticks on cattle and sheep, and crop pests such as caterpillars and grasshoppers. Some farmers encourage starlings to prey on grass grubs by placing nest boxes around fields.
However, starlings damage grapes and other fruit crops, and compete with tūī and bellbirds for the nectar of flax, rātā and other native plants. Large flocks roosting in cities soil footpaths and cars.
The common starling is from Europe, North Africa and western Asia.
Around 1,000 birds were introduced to New Zealand from the 1860s to the 1880s. Starlings are found throughout mainland New Zealand, except in densely forested or mountainous country. They have spread to the Chatham, subantarctic, Kermadec island groups, and further afield to other Pacific islands.
In the breeding season, both males and females have a glossy purple- or green-black head and breast, and yellow bill – pink at the base in females, blue in males. Their wings and underbodies have yellow-buff speckles, which, in winter, also extend over the breast and head. They are about 21 centimetres long and weigh 85 grams.
Starling nests are untidy heaps of grass in holes in trees or buildings, or at the base of clumps of vegetation. Females lay four or five pale blue eggs, and about half lay a second clutch later in the season. Life expectancy is around three years, but the oldest recorded was 14.
Outside the breeding season, starlings gather each night in sheltered communal roosts, where predators are scarce. Specific trees may be used – for example, in central Wellington large numbers used to roost in a single pōhutukawa tree on The Terrace. A little to the north, starlings congregate at dusk on pest-free Mana Island. At dawn they disperse, travelling dozens of kilometres to feed. Some roosting flocks number a million birds.
The myna (Acridotheres tristis) is native to Central Asia, from India to Afghanistan, and has been introduced around the Pacific. Although the same family as starlings, mynas are larger, measuring about 24 centimetres long and weighing 125 grams.
The body is brown, with white wing patches and a glossy black head. The myna has yellow legs, a yellow bill, and a tapered patch of yellow skin extending from the bill past its eye.
Mynas were introduced in the 1870s, mainly in the South Island, to control insect pests. They had died out there by 1890, but were common around Wellington, East Cape, and from Whanganui to Waikato. They progressively expanded northwards, reaching Auckland around 1947, and have become very abundant in Northland. Meanwhile, they disappeared from the Wellington region.
Mynas are not found in dense forest, but are common in farmland, urban gardens and on roadsides. They feed on invertebrates (including worms, snails and caterpillars), fruit, scraps and road kill, as well as lizards, eggs and chicks.
Mynas are aggressive birds with a shrill, raucous call. Because they damage fruit crops and threaten native birds, they are considered a pest in areas such as Northland.
In the breeding season, mynas have heated territorial fights. They nest mainly in holes in trees, cliffs or buildings, and sometimes remove other birds in order to use their nest holes. Females lay three to four eggs and do most of the incubating. At night males gather at communal roosts.
For the rest of the year mynas congregate in large roosting colonies. They live for up to 12 years.
The skylark (Alauda arvensis) is a northern-hemisphere species, breeding in Europe and North Africa, and across Asia to China, and migrating south to India and North Africa.
British immigrants had a sentimental attachment to skylarks, and from 1864 introduced many to New Zealand. They became common throughout the country, and are most prominent in sand dunes, open farmland and tussock grasslands.
By the early 20th century skylarks were considered second only to sparrows in causing damage to crops – pecking newly-sown seeds and pulling up sprouting wheat and other germinating plants. They became less of a problem when pastoral farming became more dominant, replacing grain cropping.
Skylarks are dark brown streaked with yellow-brown, with a white underbelly. When alert, they raise a small head crest. They weigh about 38 grams and are 18 centimetres in long.
A male skylark has a distinctive territorial display through spring and summer. He climbs steeply up to 100 metres, then hovers above his territory, trilling for minutes at a stretch, and descending in stages.
Skylarks nest in small depressions in the ground, sheltered by overhanging grasses. The birds line the nest with grass. The female lays three or four greyish-white or cream eggs, which she incubates. Both parents feed the hatchlings.
Many farmers have rued the introduction of house sparrows (Passer domesticus). They were intended to help reduce the swarms of crop-eating insect pests. However, while they do feed their nestlings on caterpillars, beetles, flies and spiders for the first week after hatching, at other times they are more interested in grains and fruit than insects. They can cause significant damage to wheat, barley and maize crops.
As few as 100 house sparrows were liberated between 1866 and 1871.
Breeding success was high – probably due to abundant food, lack of competition, a benign climate and few predators (stoats, cats and other introduced pests had not yet become widespread).
Early observers of sparrows noted that females laid eggs for a second clutch while the previous hatchlings were still in the nest. The young ones evidently helped incubate the eggs.
In 1878 naturalist Thomas Kirk calculated that one pair of house sparrows could theoretically lead to a population of 322,000 within five years.
Sparrow clubs were formed in the 1880s with the aim of reducing the sparrow plague. These were modelled on the clubs set up in England from the 1850s. Poisoned grain was laid and a bounty offered for sparrow eggs, which encouraged small boys to collect hundreds of thousands of eggs.
The Canterbury Acclimatisation Society liberated 40 sparrows in 1867. Once sparrows became a pest, the society wished to disassociate itself from any part in their introduction. They popularised the tale that in 1867 a Captain Stevens had arrived in Lyttelton with house sparrows instead of the insectivorous hedge sparrows he was commissioned to bring. The society claimed that they declined them, but that Stevens released the five house sparrows that had survived the voyage.
House sparrows are small birds, weighing about 30 grams and measuring 14 centimetres. They have a short, conical bill, like many seed-eaters. The male has a grey crown and dark chestnut nape and back, with black streaks. In the breeding season he has a large black bib with contrasting pale grey cheeks and belly. After breeding, the bib reduces to a small patch under the chin, and the black bill turns pinkish-cream.
The female has a sandy-brown back streaked with black, and pale grey undersides. She has a buff curved ‘C’ from behind the eye to the neck.
Both sexes have a single white bar on the wing.
House sparrows tend to live in association with humans, often nesting around houses and sheds, or hanging around restaurants. They can spread disease by contaminating human food.
The male builds a bulky domed nest, often in a hole. He renovates the nest periodically, even when not in use. The female lays four or more grey-white eggs with brown spots and streaks.
Finches are small birds, with short, conical beaks designed for eating seeds. Some are brightly coloured, particularly males, and most are gregarious, with tuneful songs. Four species were successfully introduced to New Zealand.
The natural range of the chaffinch (Fringilla coelebs) is from Europe and North Africa to Central Asia.
The male chaffinch has a distinctive slate-grey head and nape, and is a rich pinkish-brown underneath. The female is paler pinkish-fawn underneath, with a brown head and nape. Both male and female have a double white wing-bar.
From 1862 chaffinches were liberated by acclimatisation societies at several sites. They are now one of the most widespread species in New Zealand, including on the Chatham and Snares islands. In South Canterbury and other grain-growing areas, a bounty was introduced to control them in the early 1900s, because of the crop damage they caused.
Chaffinches are found in urban areas, farmland, orchards, shrublands, and native and introduced forest up to the subalpine zone.
They feed on fallen seed, as well as taking seeds from pine cones and grasses, and pecking at fruit. They catch insects on the wing and search foliage for caterpillars, aphids and spiders.
Chaffinches usually build their nests in mānuka, matagouri, gorse, willows or pines, and lay around four greyish-blue or pink eggs. Chicks are fed mainly invertebrates.
After breeding, they assemble in flocks of up to 600 birds.
The oldest chaffinch recorded in New Zealand was 10 years old.
The natural range of greenfinches (Carduelis chloris) is from Europe and North Africa to western Asia.
Greenfinches are olive-green with yellow outer wing feathers, and they show flashes of yellow as they fly past, often in large flocks.
Greenfinches were introduced to Nelson, Canterbury, Auckland and Otago from the early 1860s. Numbers increased rapidly and they were soon found in most parts of New Zealand.
Soon they were described as the ‘farmer’s greatest enemy when grain is ripening’. 1 Greenfinches damaged fruit trees in flower, ripe fruit, young vegetables and grains. Their numbers declined by the 1920s, as pastoral and dairy farming replaced grain cropping.
Greenfinches usually live in farmland, shelter belts, orchards and gardens. They tend to stay in one region, but have been known to move several hundred kilometres. They avoid higher country and dense bush, and in winter often feed along the coast.
A pair takes up to two weeks to build a bulky, untidy nest, usually in the outer forks of pines, mānuka, matagouri or gorse. The nest is empty for up to three weeks before the female lays four or five bluish-white eggs with brown blotches. She incubates alone, fed by the male. Nestlings are mainly fed regurgitated seeds.
The oldest recorded greenfinch in New Zealand was seven years old.
About 500 goldfinches (Carduelis carduelis) were released by acclimatisation societies between 1862 and 1883. They are native to Europe, North Africa and western Asia. Now they are spread over most of New Zealand, other than heavily forested or alpine areas. They have also reached most of the outer island groups.
Goldfinches are New Zealand’s most colourful finches. They are bright red from their bill over their face to their forehead. They have a black crown and collar, black-and-gold wings, and shades of brown, buff and white on their body.
Outside the breeding season the birds feed in large flocks of about a hundred, and fly in an undulating pattern. A record flock of 15,000 goldfinches has been observed.
Goldfinches are the most welcome small introduced bird because they feed mainly on the seed of weeds, such as thistle, rather than on grains. They also feed their chicks invertebrates, including aphids and other pests.
The female builds the nest, usually in fruit trees, grape vines and conifers. She lays four or five bluish-white eggs with reddish spots, which she incubates. The male feeds both the mother and the hatchlings.
The oldest recorded goldfinch was eight years old.
The redpoll (Carduelis flammea), the smallest of the introduced finches, is native to Europe, Asia and North America. It is now common in the South Island and lower North Island from sea level to the subalpine zone, preferring drier and higher country. In winter they gather in flocks.
The redpoll is the smallest of the finches, weighing just 12 grams and measuring about 12 centimetres. They have a streaky brown body with a red forehead, and the male has a bright crimson chest in breeding season.
Redpolls eat weeds, grass seeds and insects. They sometimes harm peach and apricot crops by destroying flower buds.
Redpolls usually nest in low bushes, laying around four bluish-green eggs with brown speckles.
Yellowhammers (Emberiza citrinella) were introduced to both the North and South islands from the 1860s, and spread quickly. By the early 20th century they were such a problem to farmers that bounties were offered. They are no longer a serious pest.
The natural range of yellowhammers is from Britain to Siberia, some migrating further south in winter. In New Zealand they range from sea level to 1,600 metres, and live in farmland, orchards and tussock country. They feed on seeds, cereal grains and invertebrates.
Yellowhammers, at about 16 centimetres long and 27 grams in weight, are similar in size to sparrows. Males have a bright-yellow head and face, and streaky reddish-brown wings and chest. Females are paler, and have a continuous brown curve from eye to chin. They dip as they fly, closing their wings momentarily.
They build their nests on the ground or in low, thick vegetation, and lay about four whitish-pink eggs with fine scribble lines, which are incubated mostly by the female.
The cirl bunting (Emberiza cirlus) was released in small numbers – seven in Otago in 1871 and four in Wellington in 1880. It has remained uncommon, with a population of just 2,000–5,000 birds. They live in the north-east South Island and eastern North Island.
The cirl bunting is native to southern Europe, North Africa and Turkey, but its hold there is tenuous, so the small New Zealand population is significant.
A close relative of the yellowhammer – and similar in size – the cirl bunting male has a black head with yellow lines above and below the eye, and a black throat and collar. The female is a pale yellow, with darker-brown face markings.
Cirl buntings build nests in low bushes or trees, and lay three bluish-green eggs with fine black streaks.
The dunnock (Prunella modularis) is also called a hedge sparrow, although it is not a true sparrow.
Several hundred dunnocks were introduced on both islands from 1867 onwards, and soon became widely established, including on the offshore islands. They range from sea level to subalpine shrublands, but are sparse in some lowland regions.
The male and female dunnock resemble the female house sparrow in colour. However, they have brown-flecked cheeks and flanks, a slimmer body and a finer bill – which is typical of insectivores.
Dunnocks frequent gardens, orchards, scrub and plantation forests. Because they eat mainly invertebrates, they are more popular with farmers and gardeners than most other small introduced birds. They are secretive, staying close to cover.
In England polygamous breeding is common, but in New Zealand simple pairs are more usual. They build their nests in dense hedge-like bush, and lay four deep-blue eggs.
Drummond, James. Our feathered immigrants: evidence for and against introduced birds in New Zealand. Wellington: Government Printer, 1907.
Heather, Barrie D., and Hugh A. Robertson. The field guide to the birds of New Zealand. Rev. ed. Auckland: Viking, 2005.
McDowall, R. M. Gamekeepers for the nation: the story of New Zealand’s acclimatisation societies, 1861–1990. Christchurch: Canterbury University Press, 1994.
Reader’s Digest complete book of New Zealand birds. Sydney: Reader’s Digest, 1985.
Thomson, G. M. The naturalisation of animals and plants in New Zealand. London: Cambridge University Press, 1922.
Wilson, Kerry-Jayne. Flight of the huia: ecology and conservation of New Zealand’s frogs, reptiles, birds and mammals. Christchurch: Canterbury University Press, 2004.