New Zealand bellbird


The New Zealand bellbird, also known by its Māori language names korimako, makomako and kōmako, is a medium-sized species of honeyeater endemic to New Zealand. It has been the only living member of the genus Anthornis since the Chatham bellbird went extinct in the early 20th century. The bellbird's closest living relative is the only other New Zealand honeyeater, the tūī. The bellbird forms a significant component of the famed New Zealand dawn chorus of birdsong, which was much noted by early European settlers. Exceptional singing abilities were already observed by Captain James Cook, who described its song as "like small bells most exquisitely tuned".
Bellbirds measure about in length, with females weighing approximately and males. Males are mostly olive-green with paler underparts, and bluish-black wings and tail. Females are paler and browner. Like other honeyeaters, the bellbird has a brush-like tongue that enables effective feeding on nectar from deep flowers. The species is common across much of New Zealand, its offshore islands, and the Auckland Islands, but it is scarce north of Waikato and across the Canterbury Plains and Central Otago. Its habitat includes both native and exotic forests and scrublands, and it is commonly found in parks and gardens.
Bellbirds feed on nectar, fruit, honeydew, and insects. During the breeding season, they become highly territorial and aggressively defend their territory against intruders. Bellbirds form monogamous pairs with long-lasting bonds that can span many years. Females typically lay around 3–4 eggs and incubate them for about 13–15 days. Fledging occurs approximately 19 days after hatching. Bellbirds have modified their ninth primary flight feathers, allowing them to produce specific whirring sounds in flight that they utilise during courtship and territorial defence. The bellbird is regarded as taonga by the Māori, who traditionally valued it for both its meat and its melodious singing abilities.

Taxonomy and nomenclature

History and names

The first Europeans to encounter New Zealand bellbirds were members of the first voyage of James Cook. When anchored at Queen Charlotte Sound, the voyage botanist Joseph Banks wrote in his diary on 17 January 1770 about a local dawn chorus: "Their voices were certainly the most melodious wild musick I have ever heard, almost imitating small bells but with the most tuneable silver sound imaginable". It is assumed that the chorus was created by bellbirds. Johann Reinhold Forster and Anders Sparrman collected the first specimens in April 1773 during Cook's second voyage. Forster illustrated the bellbird in Dusky Sound, however his illustration remained unpublished for many years. John Latham published a description of the bellbird in his 1782 work A General Synopsis of Birds. He mentioned that the bellbird "has an agreeable note" and that because of its ability to imitate the notes of other birds, "it was called by the English the Mocking-bird". Latham, who at that time created English names for species, and did not start applying Latin binomial names until a 1790 publication, assigned it to the Creeper genus and named the species the Mocking Creeper. The specimen he described was in the Leverian Museum in London, but has been lost, which probably happened when the Leverian collection was broken up and sold by auction in 1806.
Sparrman published his own description of the species in 1786 and coined the binomial name Certhia melanura. His description was based on a specimen in the private museum of in Sweden, which held birds that Sparrman had collected on the voyage with Cook and at the Cape of Good Hope, where he lived before and after the voyage. He erroneously wrote in the description that the specimen was from the Cape of Good Hope. In the past, mislabelling specimens was quite common and Sparrman made exactly the same mistake with two other New Zealand birds, the rifleman and piopio. The type locality was later corrected to Queen Charlotte Sound. Parts of Carlson's collection ended up in the Swedish Museum of Natural History and the type specimen was there as of 1857, but it was not found there in a 1926 study.
The specific name melanura means "black-tailed". In Māori, the bellbird is known by several names, including kōmako, kōparapara, korimako, makomako and kopara. The male bellbird is known as kēkerematua or kerekerematātu. The English common name "bellbird" originates from the imaginative similarity of one of its notes to the distant ringing of a bell. The subspecies epithet oneho is named after a hill on Aorangi Island. The hill was named after Oneho, the wife of Tatua, the last chief of the Ngatitoki hapū that inhabited the island until the 1820s. Obscurus, another subspecies epithet, comes from Latin obscurus.

Classification

The bellbird was originally placed into the genus Certhia. In 1840, George Robert Gray established a genus Anthornis, where he moved the bellbird. The bellbird is the type species of the genus. This classification has been widely accepted since then. For a long time, the New Zealand bellbird was the sole representative of the genus Anthornis. The Chatham bellbird, which became extinct in the early 20th century, was formerly classified as a subspecies of the New Zealand bellbird, as A. melanura melanocephala. The Chatham bellbird is now recognised as a separate species and a second member of the genus. The New Zealand bellbird and the tūī are the only representatives of honeyeaters in New Zealand. The hihi or stitchbird, another New Zealand endemic bird, was originally considered to be a honeyeater also, but it is now believed to constitute its own monotypic family Notiomystidae.
A molecular study from 2017 identified the Chatham bellbird as the closest relative to the New Zealand bellbird. Both species constitute a clade to which the tūī is a sister taxon. Other close relatives of the bellbirds and the tūī are the marbled and plain honeyeaters from New Guinea. Their phylogenetic relationships are shown in the cladogram below:

Subspecies

There are three recognised subspecies of the New Zealand bellbird with the following distribution:
Bellbirds are medium-sized honeyeaters, about 17–20 cm in length from the tip of their beak to the end of their tail. Females weigh about 25g and males 33g. Males have an olive-green body with a dark purplish sheen on their head. Their belly and flanks are lighter. The uppertail is black-brown with a narrow iridescent blue-black edge on most feathers. The upperwing coverts are mostly dark olive-green, with blackish inner webs. The vent and undertail-coverts are pale yellow to off-white, and the thighs are grey. The underwing is mainly grey with a dark olive leading edge, pale-yellow secondary coverts, and a brown tint to the remiges. There is a yellow patch at the bend of a folded wing. The iris of the male is red.
Females are slightly smaller than males. Their plumage is duller and much browner than adult males. The gloss on the head is bluish, and there is a narrow white stripe starting at the gape and continuing below the eye. Upperparts are dark olive-brown with dark brown uppertail and olive-edged outer webs. The upperwing is mostly dark olive-brown with dark brown inner webs and olive outer edges. Underparts are mostly olive-brown with a patch of pale yellow feathers on the flanks, less prominent than in adult males, and pale olive to off-white vent and undertail-coverts. The undertail is brownish grey, and the underwing resembles that of an adult male. The iris of a female is brown.
Bare parts of males and females are the same. The bill is black and slightly curved downwards. Legs are grey-black, claws brown. Similar to other honeyeaters, bellbirds have a brush-like tongue that is used to collect nectar deeply from flowers. The tongue is longitudinally grooved, and its tip is divided into four segments. The end of each segment is equipped with fine hair-like structures that form the final brush. In both sexes, the ninth primary feather is notched. Sometimes, the eighth or tenth or all three mentioned primaries are notched too.
Both subspecies oneho and obscura are very similar in appearance to the nominate species described above. Male subsp. oneho has more blue sheen on its head, and feathers on some upper parts have a violet sheen. Female subspecies oneho differs from the nominate female by having a greener sheen on the head and neck, and a green-blue sheen on the crown, forehead, nape, and ear coverts. Compared to mainland birds, males of the subsp. oneho are relatively larger in proportion to females. The male subsp. obscura has slightly darker plumage than the nominate male, and its sheen on the upper body parts is violet. The female subsp. obscura has slightly paler underparts compared to the nominate female.
A juvenile male is similar to an adult male but is duller with very little to no iridescence. A juvenile female is even paler and greyer than a juvenile male. Unlike adults, juvenile bellbirds don't have their primaries notched. Nestlings are initially born without feathers but quickly develop a covering of grey down.

Distribution and habitat

The most widespread subspecies by far is melanura, which can be found throughout North, South, Stewart and Auckland Islands. It is also present on many satellites like Tiritiri Matangi Island, Mokohinau, Little Barrier, Cuvier, Mercury, Hen and Chickens, Aldermen and Mayor Islands. Vagrants have appeared as far south as Campbell Island and there is a historical record from the Snares Islands dating back to 1888. Subsp. oneho only occurs on Three Kings Islands, and subsp. obscura only nests on Poor Knights Islands, but occasionally visits the nearby mainland of eastern Northland. Bellbirds are almost absent north of Waikato. Northland can get occasional winter female visitors from nearby offshore islands, and small pocket populations exist in some places north of Auckland like Tāwharanui Peninsula and Shakespear Regional Park. It is also scarce in the Canterbury Plains and Central Otago. In their native forest habitat, bellbirds can be abundant and are more widely distributed than tūī.
File:Anthornis melanura 25470849.jpg|left|thumb|Male bellbird on a kōwhai tree, Banks Peninsula
The bellbird's habitat encompasses both native and exotic forests and scrublands, and it is frequently found in urban areas such as parks and gardens, especially if there is a nearby patch of native bush. It is found from lowland areas at sea level up to about 1200 metres, including subalpine regions above the tree line. It particularly thrives in densely vegetated areas with a mix of podocarp-hardwood lowland forests with diverse vegetation. It is typically found in forests dominated by northern rātā, tawheowheo, kāmahi, as well as mixed southern beech forests or coastal broadleaf forests, such as pōhutukawa. Additionally, it can be found in exotic forests such as eucalyptus, acacia, and even pine and willow forests. Occasionally, it ventures into farmland, including orchards.
On predator-free islands, bellbirds typically reach higher population densities than on the mainland. On the Poor Knights Islands, subsp. oneho reaches densities of 71 birds per hectare. However, this figure was derived from a study area of only 0.45 hectares, and therefore may not accurately reflect the entire 66-hectare island. On the predator-free Great Island in the Three Kings Islands, the density of bellbirds was estimated to be 16 birds per hectare and on Tiritiri Matangi Island 2.13 pairs per hectare.