Bird Research News

Vol.10 No.5

2013.5.27.

Bonin White-eye

Meguro (Jpn) Apalopteron familiare

Morphology and classification
Classification: Passeriformes Zosteropidae
Total length:
Approximately 140mm
Wing length:60-72mmTail length:59-65mm
Culmen length: 16-20mm
Tarsus length: 23-26mm
measurements by the author.
Weight:13-17gAppearance:
Plumage of adult Bonin White-eyes
is grayish green on the head, back,tail and wings, and bright yellow
from throat to belly (Fig. 1). The billis black and legs are grayish black.
They have a white eye ring aroundthe eye as Japanese White-eyes Zosterops japonicus, but they have apattern of upside-down black triangle, hence the Japanese name"Meguro (Black eye)" (Fig. 2). Thereis no difference in feather color between male and female. In juveniles,
however, the ventral yellow is paler
and tinged with gray. The legs areshiny black. Bonin White-eyes havea longer tail and tarsus than JapaneseWhite-eyes.

twice during the breeding season. Since they are highly territorial
in the breeding season, they try to exclude other individuals from
intruding their territory. I observed how Bonin White-eyes destructed the nest in which a Japanese White-eye was incubating in
the vicinity of their own nest by pulling out the nest materials.
They are dangerous neighbors to live with. Juveniles move aroundin a flock in the non-breeding season. It is not uncommon that theyform a mixed flock with Brown-eared Bulbuls Hypsipetes amaurotis and Japanese White-eyes. Adult birds, on the other hand,usually spend the non-breeding season with their mates around thebreeding grounds. However, they occasionally join the flock. Bonin White-eyes sleep close together with their mates as in JapaneseWhite-eyes (Higuchi et al. 1984).

Nest:
Fig. 1. An adult Bonin White-eye.

Fig. 2. Head of a Bonin
White-eye. It has whiteeye rings as in JapaneseWhite-eyes.

Vocalization:
The song sounds like "Chi-yo, Cho cho chorrrree". It is reputed toresemble the song of Red-flanked Bluetails Tarsiger cyanurus(Kabaya & Matsuda 2001). This species most frequently sings justbefore the sunrise in the breeding season and rarely sings during
the daytime (Suzuki 1993). The call note sounds like "Kyooi,kyooi” and “Chieet".

They build a bowl-shaped nest in the fork of the branches of low
to tall trees at a height of 1-13 m above the ground. The nest trees
include Rhaphiolepis, Ardisia, Calophyllum, Morus, Bischofia,
Ficus and Casuarina (Morioka & Sakane 1978, Higuchi et al.
1993, Ueda et al. 1993). Bonin White-eyes do not build a hanging
nest, in contrast with many white-eye species including Golden
White-eyes Cleptornis marchei which are assumed to be closely
related to Bonin White-eyes. A single case of nesting in the hollowof Casuarina equisetifolia was reported in the past (Kawakami &Higuchi 2002).

Egg:
The clutch size is 2-4 eggs. The egg has brown flecks on a light
blue ground. The egg size is about 20 by 16 mm. The eggs are
sometimes predated by Brown-eared Bulbuls.

Incubation and nestling periods:
Incubation and nestling periods are a little less than two weeks
each. Both male and female incubate eggs and feed chicks. The
parent birds continue feeding the fledglings for up to one month.
They are overly protective of their young for a small song bird.

Distribution and Habitat
Feeding habits and foraging behavior
Distribution:
Bonin White-eyes are endemic to the Bonin Islands. It is recordedthat they occurred before WWII in Mukojima and Nakodojima
Islands of the Mukojima island group, Chichijima Island of theChichijima island group and Hahajima, Mukohjima, Imotojima
and Meijima Islands of the Hahajima island group. At the presenttime, however, they are distributed only in Hahajima, Mukohjima
and Imotojima Islands and extinct on the other islands. The lastbirds were recorded in Chichijima Island 1828 (Kittlitz 1830),Nakodojima Island 1889 (Seebohm 1890), Meijima Island 1904
(Momiyama 1930) and Mukojima Island 1930 (Yamashina 1930).
There was a captive breeding record in Ueno Zoo in 1935.

Habitat:
They occur in a wide variety of habitats, such as tall wet forests,
dry scrub forests, agricultural land and settlements. Since they
prefer forests, they are densely distributed in tall wet forests, butsparsely in open areas (Kawakami & Higuchi 2003).

Life history
12

3

4

5

6

breeding season

78910

11 12

non-breeding season

Breeding system:
Bonin White-eyes usually breed monogamously. The major breeding period is from March to July, but they occasionally breed

A field guide usually carries aphotograph of Bonin Whiteeyes eating a papaya. In fact,however, their diet consists
primarily of insects, such as
Lepidoptera larvae (Kawakami& Higuchi 2003). It occasionally captures geckoes. It is truethat Bonin White-eyes eat introduced fruits, such as papaya, Fig. 3. Fragments of ants areficus and mulberry, but thisfrequently included in thebehavior is considered to befeces of Bonin White-eyes.
overrepresented because these
The photo shows mainly thehead of ants (used for identifitrees grow in places where evecation).
ryone can see them. The yellow
plumage of this species does notcome from eating too much papayas. In addition, Bonin Whiteeyes frequently ingest ants (Fig. 3), which is a distinguishing characteristic of this species because only a limited species of birds
readily eat ants in spite of their defensive poison.
Bonin White-eyes feed on the ground and tree trunks as well as
on branches and leaves of a tree (Kawakami & Higuchi 2003). It is
assumed that this feeding behavior has evolved due to the absenceof ground predatory mammals such as foxes and tree trunk users
such as woodpeckers on the islands where Bonin White-eyes occur.

4♪ http://www.bird-research.jp/1_shiryo/koe/meguro_110416_hahajima_mju.mp3
Mutsuyuki Ueta

♪ http://www.bird-research.jp/1_shiryo/koe/meguro_110417_hahajima_mju.mp3
Mutsuyuki Ueta

Bird Research News

Vol.10 No.5

2013.5.27.

© Japan Bird Research Association
Sumiyoshi 1-29-9, Fuchu, Tokyo, Japan

Topics of ecology, behavior and conservation● How the Bonin White-eye (“Black-eye”) became a white-eye?
DNA analysis suggests that Bonin White-eyes are closely related
to Zosteropidae (Springer et al. 1995), and they are classified as aspecies of Zosteropidae in the 7th edition of Check-list of Japanese Birds. The oldest record of Bonin White-eyes was produced
in 1675 by Ichizaemon Shimaya whose party explored theOgasawara Islands and presented "five birds resembling Whiteeyes" to the Shogunate (Suzuki 2003). In the Meiji era, the species
has been referred to as an Island White-eye or Black White-eye by
the local islanders, which indicates that Bonin White-eyes wererecognized as a bird of the white-eye group. It took quite a while
for the taxonomic status of this species to finally settle, after it wasclassified such families as babblers or Pycnonotidae. It had beenclassified as a Meliphagidae until the 6th edition of Check-list ofJapanese Birds. The classifications of Bonin White-eyes havevaried with the times and field guides. You need to be carefulwhen you cite old records.

● Bonin White-eyes do not like the sea although they live inthe oceanic islands
The current distribution of Bonin White-eyes is restricted to three islands of theOgasawara Islands (Hahajima, MukohHahajima
jima and Imotojima Islands of the Hahajima island group). Forests habitablefor Bonin White-eyes remain in Hirashima, Anejima and Meijima Islands of the Mukohjima
Hahajima island group, but BoninMeijima
White-eyes do not occur in these islands. They have never been observed
Anejimaeven to temporarily move through othImotojima
ers except for the three islands mentioned above. We compared the se- Fig. 4. Differences inbase sequence bequences of the control region of mitotween the Boninchondrial DNA from the blood samples
White-eye populataken from the birds of Hahajima,
tions of the three
Mukohjima and Imotojima Islands. Theislands of the Hahajiresult showed that there was almost noma island group.
genetic exchange between the island
Color pie charts show
populations because the populations of
the proportions ofHahajima and Imotojima Islands had
individuals with adifferent base setheir distinctive sequences (Fig. 4). In
quence (haplotype).
addition, morphology, especially a bill
shape, is significantly different between
the satellite islands. These DNA analysis and morphological study
suggest that Bonin White-eyes do not basically move between theislands (Kawakami et al. 2008). These islands are separated fromeach other by only a few kilometers of the sea, but the sea seems,
nevertheless, to be an insurmountable barrier for Bonin White-eyes.
It is well known that moving and dispersing abilities decrease invarious taxa of both animals and plants in isolated oceanic islands.
Bonin White-eyes can be said to be a typical example of the island-adapted birds.

● Are Japanese White-eyes a friend or enemy?
Japanese White-eyes also occur in the Hahajima Islands. SinceJapanese White-eyes are not naturally distributed in these islands,
it is assumed that they are a hybrid of introduced Z. japonicus
alani from the Iwo Islands and Z. j. stejnegeri from the Izu Islands(Fig. 5). At first the impact of inter-specific competition on Bonin
White-eyes was concerned because Bonin White-eyes and Japa-

バードリサーチ生態図鑑
nese White-eyes are similar in body sizeand feeding habit. In spite of the fact thatJapanese White-eye population has increased, however, the population density ofBonin White-eyes has not greatly changed,
which suggests the impact of competition
between the two species has had little or no Fig. 5. Introduced
Japanese Whiteeffect on Bonin White-eyes at populationeye. Hybrid oflevel (Kawakami & Higuchi 2003).
Zosterops japoniBonin White-eyes are considered to funccus stejnegeri andtion as a disperser of small seeds in theZ. j. alani
Ogasawara Islands. However, they arealready extinct in the Chichijima Islands and the Mukojima Islands. It is assumed that introduced Japanese White-eyes haveplayed the role of a seed disperser in place of extinct Bonin Whiteeyes on these islands (Kawakami et al. 2009).

Literature
Higuchi H., Nakane M. & Maru T. 1993. Home range and pair duration of theBonin Islands Honeyeater Apalopteron familiare. Strix 12: 23-33.
Higuchi H., Nakane M. & Suzuki A. 1984. Some notes on the ecology and behavior of the Bonin Islands Honeyeater Apalopteron familiare. Tori 33: 67-73.
Kabaya T. & Matsuda M. 2001. Guide to 420 songs of Japanese Wild Birds Enlarged Ed. Shogakukan, Tokyo. [J]Kawakami K., Harada S. Suzuki T. & Higuchi H. 2008. Genetic and morphologicaldifferences among populations of the Bonin Islands White-eye in Japan. Zool.
Sci. 25:882-887. [J]Kawakami K. & Higuchi H. 2002. The first record of cavity nesting in theOgasawara Islands Honeyeater Apalopteron familiare on Hahajima, BoninIslands, Japan. Ornithol. Sci. 1:153-154.
Kawakami K. & Higuchi H. 2003. Interspecific interactions between the native andintroduced white-eyes in the Bonin Islands. Ibis 145: 583-592.
Kawakami K., Mizusawa L. & Higuchi H. 2009. Re-established mutualism in aseed-dispersal system consisting of native and introduced birds and plants on theBonin Islands, Japan. Ecol. Res. 24: 741-748.
Kittlitz F.H. 1830. Uber die Vogel der Inselgruppe von Boninsima. Mem. Acad.
Imp. St. Petersburg 1:231-248. [G]Momiyama T. 1930. On the birds of Bonin and Iwo Islands. Bulletin of the Biogeographical Society of Japan 1: 89-186. [J]Morioka H. & Sakane T. 1978. Observations of the ecology and behavior of Apalopteron familiare (Aves, Meliphagidae). Mem. Natl. Sci. Mus, Tokyo 11: 169188.
Seebohm H. 1890. On the Birds of the Bonin Islands. Ibis 32:95-108.
Springer M.S., Higuchi H., Ueda K., Minton J. & Sibley C.G. 1995. Molecularevidence that the Bonin Islands Honeyeater is a White-eye. J. Yamashina Inst.
Ornithol. 27: 66-77.
Suzuki T. 1993. Singing activity of the Bonin Islands Honeyeater Apalopteronfamiliare (Passeritormes, Meliphagidae). J. Yamashina Inst. Ornithol. 25:93101.
Suzuki T. 2003. Memorandum: birds that Japanese sailors met in the Ogasawara
Islands (Part 2). Annual Report of Ogasawara Studies 26:81-97. [J]Ueda K., Nagano Y. & Karaki M. 1993. The clutch size and the nesting locations ofBonin White-eye, Japanese White-eye, and Japanese Bush warbler in Hahajima
Island. Annual Report of Ogasawara Studies 16:18-28. [J]Yamashina Y. 1930. Birds of Parry-Group, Bonin Islands. Tori 6:323-340. [J]Languages of literature cited other than English: [J] in Japanese, [J+E] in Japanesewith English summary.

AuthorKazuto KAWAKAMI Forestry and Forest Products Research Institute
At last I have reached an pre-climactericage this year. I don't know whether it isbecause of my age, but I have spent miserable days, breaking mirrors of two
motorbikes, bumping my little finger andsuffering from hay fever. At the veryleast, I hope my latest book “A Reckless
Ornithologist Talks
aboutDinosaurs” (Gijutsuhyoronsha) sells well.
kazzto@ffpri.affrc.go.jp

5