Johann Friedrich Gmelin described the bird in 1789 as a large, conspicuous pigeon up to 50 cm (20 in) in length and 550–850 g (19–30 oz) in weight, with a white breast and iridescent green–blue plumage.

Found in a variety of habitats across the country, the kererū feeds mainly on fruits, as well as leaves, buds and flowers.

Although widespread in both forest and urban habitats, its numbers have declined significantly since European colonisation and the arrival of invasive mammals such as rats, stoats and possums.

However, the results of nationwide bird surveys indicate that there has been a significant recovery in the population of kererū in suburban areas.

This issue has received significant public and political attention, as some people argue that bans on kererū hunting are detrimental to Māori traditions.

English ornithologist John Latham wrote about the kererū in his A General Synopsis of Birds in 1783 but did not give it a scientific name.

[11] The kererū belongs to the family Columbidae, and the subfamily Ptilinopinae, which is found throughout Southeast Asia, Malaya, Australia and New Zealand.

[16][17][18][19][20][21] Spelling Māori loanwords with macrons — that indicate a long vowel — is now common in New Zealand English where technically possible.

[7] Its appearance is that of a typical pigeon, in that it has a relatively small head, a straight soft-based bill and loosely attached feathers.

[17] Its lack of genetic diversity suggests the species retreated to forest refugia during periods of Quaternary glaciation and rapidly spread across the country again when the climate grew warmer.

[29] They can be found in a variety of habitats including in native lowland forest, scrub, the countryside, and city gardens and parks.

[7] A 2011 study in Southland revealed that three of four kererū tagged around Invercargill crossed the Foveaux Strait to Stewart Island, and travelled up to 100 km (62 mi).

[32] The kererū is primarily frugivorous, preferring fruit from native trees, but also eating leaves, flowers and buds.

[28][33] The kererū feeds on many species with tropical affinities, including the Lauraceae and Arecaceae,[34][35][36] which abound in the essentially subtropical forests of northern New Zealand.

[34][35][36][37] Other fruit sought after by kererū include those of tawa (Beilschmiedia tawa), taraire (Beilschmiedia tarairi), pūriri (Vitex lucens), pigeonwood (Hedycarya arborea), as well as tītoki (Alectryon excelsus), nīkau (Rhopalostylis sapida), karaka (Corynocarpus laevigatus), Coprosma, and introduced species such as elder (Sambucus nigra), privet (Ligustrum species) and plums.

[38] Because of its diverse diet and widespread distribution, the kererū plays an important ecological role, and is vital to the health of podocarp-broadleaf forest.

[39][40] While fruit comprises the major part of its diet, the kererū also browses on leaves and buds from a wide variety of both native and exotic species, especially nitrogen-rich foliage during breeding.

In the warmer Northland region, kererū are able to raise young year round, provided enough fruit is available.

[40] 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.

The courtship display includes the male turning around on a perch adjacent to a female, placing the tip of the bill into a wing, and stretching out his neck while bowing his head.

[47] Kererū were numerous until the 1960s, but they have since come under threat from introduced mammalian species, hunting, habitat degradation, and poor reproductive success.

A large number of kererū fatalities have been reported alongside State Highway 2 in Wellington, as a result of low-flying birds being struck by vehicles as they fly across the motorway to feed on the flowers of tree lucerne.

The proposed solution was the installation of a grid of dots permanently fixed to approximately 150 m2 (1,600 sq ft) of glass.

[65] Kererū were the food of choice associated with Puanga celebrations as the birds are fat from eating berries that ripen during this time.

[48][67] They were so abundant that New Zealand ornithologist Walter Buller reported at least 8000 birds were caught and prepared in this manner from a grove of miro near Lake Taupō over July and August 1882.

[18] In 1994, the New Zealand Conservation Authority published a discussion paper about allowing the harvest of various species protected under the Wildlife Act 1953, including the kererū.

[79] It has been argued that preventing the customary harvests of taonga such as kererū is in-part degrading or facilitating the loss of mātauranga (traditional knowledge) among Māori.