The Bonin white-eye (''Apalopteron familiare'') or is a small songbird
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
to the
Bonin Islands
The Bonin Islands, also known as the , are an archipelago of over 30 subtropical and tropical islands, some directly south of Tokyo, Japan and northwest of Guam. The name "Bonin Islands" comes from the Japanese word ''bunin'' (an archaic readi ...
(Ogasawara Islands) of Japan. It is the only species in the genus ''Apalopteron''. Its taxonomic affinities were a long-standing mystery and it has been placed with the
bulbul
The bulbuls are members of a family, Pycnonotidae, of medium-sized passerine songbirds, which also includes greenbuls, brownbuls, leafloves, and bristlebills. The family is distributed across most of Africa and into the Middle East, tropical As ...
s,
babblers and more recently with the
honeyeater
The honeyeaters are a large and diverse family (biology), family, Meliphagidae, of small to medium-sized birds. The family includes the Epthianura, Australian chats, myzomelas, friarbirds, wattlebirds, Manorina, miners and melidectes. They are ...
s, during which it was known as the Bonin honeyeater. Since 1995 it is known to be a
white-eye
The white-eyes are a family, Zosteropidae, of small passerine birds native to tropical, subtropical and temperate Sub-Saharan Africa, southern and eastern Asia, and Australasia. White-eyes inhabit most tropical islands in the Indian Ocean, the ...
in the family Zosteropidae, that is closely related to the
golden white-eye
The golden white-eye (''Cleptornis marchei'') is a species of bird in the white-eye family, Zosteropidae. It is the only species within the genus ''Cleptornis''. The golden white-eye was once considered to be a honeyeater in the family Melipha ...
of the Marianas Islands.
The Bonin white-eye has predominately yellow and green
plumage
Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...
and a conspicuous black triangular patch around the eye – the eye is also surrounded by a broken white ring. It was once found on all the major islands of the Bonin Islands but is now restricted to the islands of
Hahajima
, native_name_link =
, image_caption = Map of the Hahajima Rettō (Imōtojima is mislabeled as Tori-shima)
, image_size =
, pushpin_map = Japan complete
, pushpin_label = Hahajima
, pushpin_label_position =
, pushp ...
. On that island group it is found in almost all the habitat types, native and human-modified, although it mostly breeds in native forest. Fruit is an important part of the diet, especially mulberries, as well as insects, but flowers, seeds, spiders and reptiles are taken as well. It feeds both in trees and on the ground, as it is more terrestrial than other white-eyes. Pairs of Bonin white-eyes form long-term pair bonds and remain together throughout the year. They nest in a cup-shaped nest into which usually two eggs are laid. Both parents are responsible for incubation and raising the chicks.
The arrival of humans in the Bonin Islands resulted in the
extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually 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 ...
of many of the native birds of the islands. The Bonin white-eye was affected by the changes that caused those extinctions, and has lost one subspecies and is no longer found on many groups of the Bonin Islands. The species is an important part of the ecology of the Bonin Islands, an important
seed disperser
In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant.
Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...
for the native plants. It has proven to be somewhat resilient to competition from introduced
warbling white-eye
The warbling white-eye (''Zosterops japonicus''), also known as the Japanese white-eye and mountain white-eye, is a small passerine bird in the white-eye family. The specific epithet is occasionally written ''japonica'', but this is incorrect due ...
s, predation by
introduced rats and cats, and habitat loss. The Bonin white-eye is evaluated as being "
near threatened
A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...
" by the
IUCN Red List of Threatened Species
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...
.
Taxonomy
The Bonin white-eye was described by
Heinrich von Kittlitz Friedrich Heinrich, Freiherr von Kittlitz (16 February 1799 – 10 April 1874) was a Prussian artist, naval officer, explorer and naturalist. He was a descendant of a family of old Prussian nobility ("Freiherr" meaning "independent lord" - ranking w ...
in 1830 based on specimens collected on
Chichijima
, native_name_link =
, image_caption = Map of Chichijima, Anijima and Otoutojima
, image_size =
, pushpin_map = Japan complete
, pushpin_label = Chichijima
, pushpin_label_position =
, pushpin_map_alt =
, ...
in the
Bonin Islands
The Bonin Islands, also known as the , are an archipelago of over 30 subtropical and tropical islands, some directly south of Tokyo, Japan and northwest of Guam. The name "Bonin Islands" comes from the Japanese word ''bunin'' (an archaic readi ...
.
Kittlitz placed the species in the
bulbul
The bulbuls are members of a family, Pycnonotidae, of medium-sized passerine songbirds, which also includes greenbuls, brownbuls, leafloves, and bristlebills. The family is distributed across most of Africa and into the Middle East, tropical As ...
(family
Pycnonotidae
The bulbuls are members of a family, Pycnonotidae, of medium-sized passerine songbirds, which also includes greenbuls, brownbuls, leafloves, and bristlebills. The family is distributed across most of Africa and into the Middle East, tropical Asi ...
) genus ''
Ixos
''Ixos'' is a genus of passerine birds in the bulbul family (biology), family, Pycnonotidae.
Taxonomy and systematics
The genus ''Ixos'' was introduced in 1825 by the Dutch zoologist Coenraad Jacob Temminck to accommodate the Javan bulbul. The ...
''.
He gave the species the specific name from the Latin for familiar or friendly, as the species was the first bird that visitors would encounter, much like the
house sparrow
The house sparrow (''Passer domesticus'') is a bird of the sparrow family Passeridae, found in most parts of the world. It is a small bird that has a typical length of and a mass of . Females and young birds are coloured pale brown and grey, a ...
in Europe.
In 1854
Charles Lucien Bonaparte
Charles Lucien Jules Laurent Bonaparte, 2nd Prince of Canino and Musignano (24 May 1803 – 29 July 1857), was a French naturalist and ornithologist. Lucien and his wife had twelve children, including Cardinal Lucien Bonaparte.
Life and career
...
moved it to its own genus, ''Apalopteron''. The name is derived from the
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
for delicate and for feather.
Bonaparte also placed it with the
Old World babbler
The Old World babblers or Timaliidae are a family of mostly Old World passerine birds. They are rather diverse in size and coloration, but are characterised by soft fluffy plumage. These are birds of tropical areas, with the greatest variety in S ...
s, then a subgrouping (Timaliini) of an enlarged Old World warbler family (
Sylviidae
Sylviidae is a family of passerine birds that includes the typical warblers and a number of babblers formerly placed within the Old World babbler family. They are found in Eurasia and Africa.
Taxonomy and systematics
The scientific name Sylviid ...
).
Richard Bowdler Sharpe
Richard Bowdler Sharpe (22 November 1847 – 25 December 1909) was an English zoologist and ornithologist who worked as curator of the bird collection at the British Museum of natural history. In the course of his career he published several mono ...
moved it back to the bulbul family in 1882, and placed it in the genus ''
Pycnonotus
''Pycnonotus'' is a genus of frugivorous passerine birds in the bulbul family Pycnonotidae.
Taxonomy and systematics
The genus ''Pycnonotus'' was introduced by the German zoologist Friedrich Boie in 1826 with the Cape bulbul as the type specie ...
''. It was moved back to the babblers again by
Jean Théodore Delacour
Jean Théodore Delacour (26 September 1890 – 5 November 1985) was a French ornithologist and aviculturist. He later became American. He was renowned for not only discovering but also rearing some of the rarest birds in the world. He establish ...
in 1946,
before
Herbert Girton Deignan
Herbert Girton Deignan (December 5, 1906 – March 15, 1968) was an American ornithologist who worked extensively on the birds of Thailand.
Deignan was born in New Jersey, the son of Harry Francis and Anna Galena. He grew up in Pennsylvania and ...
placed it with the Australasian
honeyeater
The honeyeaters are a large and diverse family (biology), family, Meliphagidae, of small to medium-sized birds. The family includes the Epthianura, Australian chats, myzomelas, friarbirds, wattlebirds, Manorina, miners and melidectes. They are ...
s (family Meliphagidae) in 1958, on the basis of tongue structure, bill shape, nest structure and a number of other morphological features.
The species remained with the honeyeaters for many decades, although some authors questioned the placement, especially as it was the only honeyeater in the North Pacific and there were no members of that family in the Philippines, the island group between that family's natural range and the Bonin Islands.
Finn Salomonsen
Finn Salomonsen (31 January 1909 – 23 April 1983) was a Danish ornithologist. He is best known for his work on the birds of Greenland.
His interest in Greenland began at the age of 16 when he made a trip with Lehn Schioler to the Upernavik Dist ...
, writing in 1967, thought that the
golden white-eye
The golden white-eye (''Cleptornis marchei'') is a species of bird in the white-eye family, Zosteropidae. It is the only species within the genus ''Cleptornis''. The golden white-eye was once considered to be a honeyeater in the family Melipha ...
(''Cleptornis marchei'') of the
Marianas Islands
The Mariana Islands (; also the Marianas; in Chamorro: ''Manislan Mariånas'') are a crescent-shaped archipelago comprising the summits of fifteen longitudinally oriented, mostly dormant volcanic mountains in the northwestern Pacific Ocean, betw ...
might be a close relative, and the species was then known as the golden honeyeater.
Hiroyuki Morioka and Takaharu Sakane also attributed the species to the honeyeaters, but cautioned that this was a provisional placement as the structure of the tongue was not very different from that of babblers. They also noted that it was very similar in diet and habitat preferences to the
warbling white-eye
The warbling white-eye (''Zosterops japonicus''), also known as the Japanese white-eye and mountain white-eye, is a small passerine bird in the white-eye family. The specific epithet is occasionally written ''japonica'', but this is incorrect due ...
, which had been introduced and was coexisting with the Bonin white-eye.
The discovery that the golden white-eye was indeed a
white-eye
The white-eyes are a family, Zosteropidae, of small passerine birds native to tropical, subtropical and temperate Sub-Saharan Africa, southern and eastern Asia, and Australasia. White-eyes inhabit most tropical islands in the Indian Ocean, the ...
and not a honeyeater, based on behavioural observations by
H. Douglas Pratt Harold Douglas Pratt Jr. (born July 23, 1944, in Charlotte, North Carolina), often credited in the short form H. Douglas Pratt or as Doug Pratt, is an American ornithologist, bio acoustican, wildlife photographer, bird illustrator, and musician. His ...
and the genetic research of
Charles Sibley
Charles Gald Sibley (August 7, 1917 – April 12, 1998) was an American ornithologist and molecular biologist. He had an immense influence on the scientific classification of birds, and the work that Sibley initiated has substantially altered our u ...
and
Jon E. Ahlquist, was the impetus for the resolution of the Bonin white-eye's family placement. Sibley came to suspect that this meant that the Bonin white-eye had been similarly misassigned to the honeyeaters. Hiroyoshi Higuchi independently had reached the same conclusion, and so Higuchi and Keisuke Ueda obtained specimens for Sibley, who enlisted Mark S. Springer to analyse them using RNA sequencing. In 1995 they were able to show that it was indeed a white-eye (family Zosteropidae), and closely related to the golden white-eye and the white-eyes of the genus ''
Rukia
'' Rukia '' is a small genus of birds in the white-eye family. Its two members are found in the Federated States of Micronesia on the island of Pohnpei and the Faichuk group of the Chuuk islands. They are:
* Long-billed white-eye, ''Rukia lon ...
'' of Micronesia. The molecular evidence was supported by behavioural similarities to the white-eyes, such as the highly social
allopreening
Preening is a found in birds that involves the use of the beak to position feathers, interlock feather that have become separated, clean plumage, and keep ectoparasites in check. Feathers contribute significantly to a bird's insulation, waterp ...
and maintaining close contact when roosting.
There are two subspecies of Bonin white-eye, the extinct
nominate
Nomination is part of the process of selecting a candidate for either election to a public office, or the bestowing of an honor or award. A collection of nominees narrowed from the full list of candidates is a short list.
Political office
In the ...
, formerly found in
Mukojima is a Japanese surname. It may also refer to:
* , Japanese footballer
* , Japanese footballer
* Mukojima islands, a subgroup of the Bonin Islands
** Mukojima, one of the Mukojima islands
* Mukojima, a former ward that's now part of the special ward ...
and Chichijima,
and the southern subspecies, ''A. f. hahasima'', of
Hahajima
, native_name_link =
, image_caption = Map of the Hahajima Rettō (Imōtojima is mislabeled as Tori-shima)
, image_size =
, pushpin_map = Japan complete
, pushpin_label = Hahajima
, pushpin_label_position =
, pushp ...
.
Description
The Bonin white-eye is long and weighs around . The nominate race has a yellow head with a conspicuous triangular black eye-patch which is linked by the thin black line to a black forehead. The white eye-ring is broken by a thin black line through the eye. The are yellow, as are the throat and upper breast. The back and wings are olive-green tinged with grey, and the are tinged with brown. The tail is olive-brown, and the underparts are pale yellow, with a grey wash on the . The iris of the eye is brown, and the bill and legs are dark grey. The sexes are alike, and juveniles look very similar to the adults. The race '' hahasima'' is very similar to the nominate race, but the upperparts are tinged in yellowish-green tinge. It also has a slightly larger bill and .
Flight
Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere (i.e. air flight or aviation) or through the vacuum of outer space (i.e. spaceflight). This can be a ...
in this species is generally slow and direct, with fast sustained flight only being observed in chases between rivals. Aside from the chases, gliding and hopping were more common than flight, and individuals would usually climb trees by climbing branches and hopping; direct flights from the ground to the canopy are rare. The tarsus is long and the toes and claws are strong, especially compared to white-eyes in the genus ''
Zosterops
''Zosterops'' (meaning "eye-girdle") is a genus of passerine birds containing the typical white-eyes in the white-eye family Zosteropidae. The genus has the largest number of species in the white-eye family. They occur in the Afrotropical, Indo ...
'', reflecting its more terrestrial lifestyle. On the ground it hops rather than walks, in the manner of a
thrush.
Distribution and habitat
![Ogasawara islands](https://upload.wikimedia.org/wikipedia/commons/f/f2/Ogasawara_islands.png)
The Bonin white-eye is, at its name suggests,
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
to the Bonin Islands, south of Japan. The species was once found on all the major groups of islands in the chain, including the Mukojima Group, the Chichijima Group and the Hahajima. Presently its habitat is restricted to Hahajima Island and two nearby islands, having become extinct across the rest of its previous range. The species' presence on Chichijima Island has been the subject of debate and dispute. The species has been introduced to Chichijima from Hahajima, so it was assumed that all records related to that introduction, but its natural presence on the island, and subsequent extinction, was subsequently established from early accounts, and a bird from that island was the type specimen for the species.
All records of the species in the Chichijima Group are from the main Chichijima Island.
On Hahajima, the only island on which its habitat preferences have been studied, the species occupies almost every habitat type. It occupies undisturbed native evergreen and broadleaf forest, dominated by ''
Schima
''Schima'' is a genus of evergreen trees belonging to the tea family, Theaceae.
The genus inhabits warm temperate to subtropical climates across southern and southeastern Asia, from the eastern Himalaya of Nepal and eastern India across Indochin ...
'' and ''
Ardisia
''Ardisia'' (coralberry or marlberry) is a genus of flowering plants in the family Primulaceae. It was in the former Myrsinaceae family now recognised as the myrsine sub-family Myrsinoideae. They are distributed in the Americas, Asia, Australia, ...
'', as well as secondary and disturbed forest and other human modified habitats.
The species occupies a wide range of modified habitats during the non-breeding season, but is more localised when breeding, when it is predominantly found in undisturbed native forest with large trees and bamboo, tree ferns and large shrubs. It is much rarer on the windy ridges of the mountains, where the vegetation is short and shrubby. Local fishermen on Hahajima have reported that the species disperses to the smaller islands of the group during the autumn and winter, but these localised
movements
Movement may refer to:
Common uses
* Movement (clockwork), the internal mechanism of a timepiece
* Motion, commonly referred to as movement
Arts, entertainment, and media
Literature
* "Movement" (short story), a short story by Nancy Fu ...
have not been confirmed.
Behaviour
Vocalisations
The Bonin white-eye was long thought to be an infrequent
songster
A "songster" is a wandering musician, usually but not always African-American, of the type which first appeared in the late 19th century in the southern United States.
Songsters in American culture
The songster tradition both pre-dated and co-exi ...
. Early accounts reported no singing from captive birds, and a report published in 1985 noted that while it did sing, it did so very irregularly. The same report concluded that the species did not use its call for territorial defence.
Subsequent research found that the species does indeed sing regularly, but does so very early in the morning, just before dawn, and then only rarely during the rest of the day. The function of the song is considered more likely related to territorial defence.
Around 90% of paired and territory-holding males sing, along with some unpaired males, making the morning song a convenient tool to survey the species.
The song itself is melodious and has been compared to that of a
bunting
Bunting may refer to:
Animals Birds
* Bunting (bird) or Emberizidae, a family of Eurasian and African passerine birds
* New World buntings or ''Passerina'', a genus of American passerine birds in the family Cardinalidae
* Blue bunting, a species ...
or a
Siberian blue robin
The Siberian blue robin (''Larvivora cyane'') is a small passerine bird that was formerly classified as a member of the thrush family, Turdidae, but is now more generally considered to belong to the Old World flycatcher family, Muscicapidae. It ...
, and is a ''chew-i, chit-chit-pee, chot-chot-pee, ch-ee'' or ''tu-ti-ti, ti-titu-tuoo''.
The species makes a variety of other calls as well. It frequently makes a ''fe-ee'' contact call, as well as ''ch-ee'' or ''chit'' alarm calls, and a scolding ''kyok'' call, made when observers came too close to the nest. The male also makes a ''ze-ze-ze'' call during courtship feeding.
Diet and feeding
![Calophyllum inophyllum in Bonin Islands](https://upload.wikimedia.org/wikipedia/commons/3/30/Calophyllum_inophyllum_in_Bonin_Islands.jpg)
The Bonin white-eye has a diet that includes a range of fruit, flowers and insects. The species feeds in a wide range of
niches, both arboreal and terrestrial, and has evolved to do so. Hiroyuki suggested that its morphology and feeding habits evolved in the lack of
competition
Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indivi ...
, as the Bonin Islands are species poor in terms of birds. Feeding niches vary somewhat by season, as it feeds less frequently on the ground in the breeding season.
Fruit, seeds, flowers and nectar forms around half the diet based on direct observation, with the species observed feeding on 15 species of plant. Endemic mulberries (''
Morus boninensis Morus may refer to:
People
* Alexander Morus (1616–1670), Franco-Scottish Protestant preacher
* Henryk Moruś (1943–2013), Polish serial killer
* Huw Morus (1622–1709), Welsh poet
* Thomas More or Morus (1478–1535), English philosopher
* M ...
'') are a favoured food, but a range of fruits and flowers are fed on, both species native to the island and introduced. Among the natives fed on other than mulberries are ''
Rhaphiolepis
''Rhaphiolepis'' ( or ;The first pronunciation is that expected for Anglo-Latin; the second is common in nurseries. ''Sunset Western Garden Book,'' 1995:606–607. However, William T. Stearn in his book ''Botanical Latin'' says "Botanical Latin ...
'', ''
Leucaena
''Leucaena'' is a genus of flowering plants in the mimosoid clade of the subfamily Caesalpinioideae of the family Fabaceae. It contains about 24 species of trees and shrubs, which are commonly known as leadtrees. They are native to the Americas, ...
'', and ''
Solanum nigrum
''Solanum nigrum'', the European black nightshade or simply black nightshade or blackberry nightshade, is a species of flowering plant in the genus ''Solanum'', native to Eurasia and introduced in the Americas, Australasia, and South Africa. Ripe ...
''. Introduced plants fed on include
banana
A banana is an elongated, edible fruit – botanically a berry – produced by several kinds of large herbaceous flowering plants in the genus ''Musa''. In some countries, bananas used for cooking may be called "plantains", distinguis ...
s,
papaya
The papaya (, ), papaw, () or pawpaw () is the plant species ''Carica papaya'', one of the 21 accepted species in the genus ''Carica'' of the family Caricaceae. It was first domesticated in Mesoamerica, within modern-day southern Mexico and ...
, ''
Lantana
''Lantana'' () is a genus of about 150 species of perennial flowering plants in the verbena family, Verbenaceae. They are native to tropical regions of the Americas and Africa but exist as an introduced species in numerous areas, especially in ...
'', ''
Cucurbita moschata
''Cucurbita moschata'' is a species originating in either Central America or northern South America. It includes cultivars known as squash or pumpkin. ''C. moschata'' cultivars are generally more tolerant of hot, humid weather than cultivars of ' ...
'' (or squash) and ''
Calophyllum inophyllum
''Calophyllum inophyllum'' is a large evergreen plant, commonly called tamanu, oil-nut, mastwood, beach calophyllum or beautyleaf. It is native to tropical Asia and Wallacea. Due to its importance as a source of timber for the traditional shipbu ...
''. The Bonin white-eye does take some nectar but the extent to which it is an important food is unknown; observations on Hahajima showed it fed from flowers far less frequently than the warbling white-eye.
In addition to plant food, insect and other invertebrate prey is taken as well. Insects found in the stomachs of Bonin white-eyes include
beetles
Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
,
lacewings
The insect order Neuroptera, or net-winged insects, includes the lacewings, mantidflies, antlions, and their relatives. The order consists of some 6,000 species. Neuroptera can be grouped together with the Megaloptera and Raphidioptera in the ...
,
true bugs
Hemiptera (; ) is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from to aroun ...
, and
ants
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22,00 ...
.
They have also been observed taking caterpillars, crickets, and flies. Non-insect prey includes spiders and even small reptiles.
Breeding
The breeding behaviour of the Bonin white-eye has not been extensively studied. The main breeding season is between March and June with a peak in May. It is thought that the species forms long term pair bonds with partners remaining close throughout the year, as roosting birds typically do so in pairs. They typically place the nest in a fork in a tree (typically ''Shima'', but other trees may be used including introduced species) between off the ground,
with the average height being , but in one case a nest has been found in a cavity inside a tree. Both parents are responsible for building the nest, which is a deep and crudely shaped cup.
The nest is mostly made from ''
Pandanus
''Pandanus'' is a genus of monocots with some 750 accepted species. They are palm-like, dioecious trees and shrubs native to the Old World tropics and subtropics. The greatest number of species are found in Madagascar and Malaysia. Common names ...
'' fibres, with vines, grasses, pine needles and rootlets woven in, and the outside is lined with dead leaves. Slightly finer material is used to line the inside of the nest.
The eggs of the Bonin white-eye measure 19.5–20.5 mm × 15–15.8 mm (0.77–0.81 in × 0.59–0.62 in) and are greenish-blue spotted and blotched with brown. The usual clutch size is around two eggs, which is a small clutch for a Japanese bird.
Both parents incubate the eggs for just under two weeks and feed the chicks for a month after fledging.
Ecology
![Zosterops japonicus 02](https://upload.wikimedia.org/wikipedia/commons/d/d4/Zosterops_japonicus_02.jpg)
The introduction of warbling white-eyes led to some concerns that it would compete with the Bonin white-eye in a harmful way. Studies of the interactions of the two species has shown that this has not been the case, possibly because of differences in morphology. The Bonin white-eye does show some changes in feeding niches in the presence of the warbling white-eye, feeding lower down in the canopy when the warbling white-eye is present, but its population, food selection, or the size of its chicks have not been affected. Juvenile Bonin white-eyes join warbling white-eyes and
brown-eared bulbul
The brown-eared bulbul (''Hypsipetes amaurotis'') is a medium-sized bulbul native to eastern Asia. It is extremely common within the northern parts of its range and can be found from southern Sakhalin to the northern Philippines.
Taxonomy and ...
s in
mixed species feeding flock
A mixed-species feeding flock, also termed a mixed-species foraging flock, mixed hunting party or informally bird wave, is a flock of usually insectivorous birds of different species that join each other and move together while foraging. These ar ...
s in the non-breeding season.
Brown-eared bulbuls may sometimes take Bonin white-eye eggs.
Warbling white-eyes may have had some effect on the behaviour of Bonin white-eyes, having potentially taught the Bonin white-eye about new foods in the human-altered Bonin Islands. This ability to learn about new foods from the warbling white-eye was shown by establishing food stations on the island baited with a novel food item, tinned peaches. When first presented with the new food item, it was avoided by the Bonin white-eyes. Where Bonin white-eyes could watch warbling white-eyes feeding on the peaches they began to feed on them as well, but where warbling white-eyes were not around and could not be watched they did not do so.
The Bonin white-eye is an important
seed disperser
In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant.
Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...
in the Bonin Islands, helping to maintain healthy forests. The islands have few species of birds, particularly after the loss of several endemic species to extinction since the arrival of humans, such as the
Bonin wood pigeon and
Bonin thrush
The Bonin thrush (''Zoothera terrestris''), also known as Kittlitz's thrush or the Bonin Islands thrush, is an extinct species of Asian thrush. It is sometimes separated as the only species of the genus ''Cichlopasser''. The only place where thi ...
. In a study of native and introduced birds on the islands, it was one of the three most important seed dispersers, along with the brown-eared bulbul and warbling white-eye.
Status and conservation
![View from Hahajima-Island and the Minamizaki Tokyo,JAPAN](https://upload.wikimedia.org/wikipedia/commons/8/81/View_from_Hahajima-Island_and_the_Minamizaki_Tokyo%2CJAPAN.jpg)
The Bonin white-eye is evaluated as being "
near threatened
A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...
" by the
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
.
The nominate race, of Mukojima and Chichijima is thought to be extinct. Its current status on Chichijima is uncertain, and it was reintroduced there and may have persisted,
although a 2003 study of the species found none there.
The reasons for its extinction on these two islands are unknown.
It is thought that habitat loss, specifically the clearance of primary forest, may be a cause.
The species' status on Hahajima seems more secure. It was considered
vulnerable, as population estimates put the number of birds on the island at around 4,000. More accurate censusing, which took into account both densities of birds and how they varied by habitat, re-estimated the population at over 15,000. The same study evaluated that the species was not in immediate threat of extinction. On the basis of the study it was downlisted to near threatened in 2013.
The species is preyed upon by introduced cats; it is particularly vulnerable due to its tendency to feed on the ground,
and its nests are raided by introduced rats. It is also somewhat threatened by the loss of native forest, for agriculture and tourism. Overall however the species is resilient to some degree to habitat modification, introduced predators and competitors, and its population is thought to be stable. It remains listed as near threatened, in spite of the stable population, due to a susceptibility to extreme weather events which could decimate the species.
The Bonin white-eye is protected under Japanese law as a National Endangered Species.
The Bonin Islands have been designated a National Wildlife Protection Area, in part to help protect this species. Efforts are underway to remove cats and rats from the islands, as well as remove invasive trees and restore native trees. Conservationists have suggested that regular monitoring of the species be started and the feasibility of
translocating birds to islands they have been lost from to create more populations and lessen the risk of a single incident wiping the species out.
See also
*
References
External links
BirdLife Species Factsheet.Photo of Bonin White-eye
{{Taxonbar, from=Q253644
white-eye, Bonin
Endemic birds of Japan
white-eye, Bonin
Near threatened animals
Near threatened biota of Asia
Birds described in 1830
Taxa named by Heinrich von Kittlitz