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The New Zealand native pigeon, called kereru in the Maori language, is the largest of the four species of pigeons and doves found in the country. Altogether 280 species have been recorded in the family Columbidae that are found in most parts of the world except for polar and subpolar regions and some oceanic islands. The kereru is endemic to New Zealand and is commonly known as the wood pigeon.

Life Cycle

The kereru, Hemiphaga novaeseelandiae, is plump and richly colored, with purple head and nape, iridescent green face, throat and breast and lower back and distinctive white ‘bib’ or under parts which make it easy to distinguish among the leaves. It is commonly called the wood pigeon but is not the same as the Wood Pigeon (Columba palumbus), which is a member of a different genus.

The kereru is widely distributed in the forested areas, feeding on young leaves, fruits and flowers of many native and exotic trees and shrubs. It is different in appearance to the familiar birds of public parks and city squares, which are the introduced species and descendants of the European rock dove, Columba livia. The kereru usually weighs between 550-850 grams and grows to 20 inches in length. Though the life span of the kereru is 20 years, the average life span has reduced to five years due to the various threats it faces in today’s environment.

The kereru breeds between the months from September to March, depending on the availability of ripe fruits. It builds a flimsy nest of twigs and sticks in shrubs, trees and palms and lays a single egg each season. The egg has an incubation period of around 30 days. The young bird then takes another 36 days to fledge. In seasons of plentiful fruit the pigeons can successfully nest up to four times.

Significance

The Maori, the early inhabitants of New Zealand, had an intimate knowledge of the birds and their habits. This knowledge was the basis of the characteristics and significance given to the bird figures of their legends and proverbs. The kereru, that gorged themselves on berries until they were almost too heavy to fly were proverbial symbols of greed!!

The kereru population was numerous until about the 1860s and large flocks used to congregate in fruiting trees to feed. The kereru is large and not difficult to catch and hence became an important food for the Maori. The Europeans who arrived later learnt from the Maori about birds that were good to eat and the then plentiful pigeons provided many a good meal to supplement an otherwise meager diet. Pigeon fat was even used as a substitute for butter.

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Ecological Importance

The kereru play an important ecological role, as they are the only birds capable of eating the largest native fruits and drupes (those with smallest diameter greater than 1 cm), thus spreading the seeds intact.

The kereru population has dwindled considerably after the arrival of humans in New Zealand, and this trend continues, especially in the North Island, but is still relatively common in the west of the South Island and in coastal Otago. They are commonly found in native forests (lowlands in particular), scrub, rural and city gardens and parks.

The introduced Australian common brushtail possum and introduced species of rats — the ship or black rat, the Polynesian rat and brown rat — have significantly reduced the amount of fruit available for pigeons and other native birds. The possum and rats also prey on eggs and nestlings.

Conservation

A number of birds endemic to New Zealand belong to families that have no close relatives anywhere else in the world – which suggests that they arrived in very early times. The kereru is endemic to New Zealand and the Norfolk Island. The Norfolk Island kereru, which is  one of the subspecies, is now extinct. The other two subspecies have survived of which one is found in the mainland and the other in the Chatham Islands. Pigeon populations are also under threat from hunting, habitat degradation, poor reproductive success and reduced life span.

The Kereru Discovery Project works to create awareness among the people of New Zealand providing information on how to make their gardens kereru-friendly. Its aims are:

• Change people’s behaviours to create an environment that ensures a sustainable future for Kereru
• Build a knowledge base of key information accessible to the community
• Combine individual strengths to provide a team that is more effective than the partners alone

For more information on their work log on to: The Kereru Discovery Project

The good news is that over the last 25 years, kereru numbers have actually increased as a result of conservation activities by many community groups, local councils, the Department of Conservation and private individuals. Hence the importance of urban garden areas for the continued survival of kereru and a number of other species is being recognized.

The kereru is just one of the many species inhabiting the earth. It is the responsibility of us humans to make sure we protect them and their habitats for future generations.