_Zosterops hypolais_ Hartlaub and Finsch, Proc. Zool. Soc. London,
1872, p. 95. (Type locality, Uap.)
_Zosterops hypolais_ Gräffe, Journ. Mus. Godeffroy, 2, 1873, p.
122 (Yap); Giebel, Thes. Ornith., 3, 1877, p. 776 (Carolinae=Yap);
Schmeltz and Krause, Ethnogr. Abth. Mus. Godeffroy, 1881, p. 391
(Yap); Gadow. Cat. Birds British Mus., 9, 1884, p. 186 (Uap);
Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no. 6,
1890-1891 (1891), p. 37 (Uap); Oustalet, Nouv. Arch. Mus. Hist.
Nat. Paris, (3), 7, 1895, p. 208 (Uap); Bolau, Mitteil. Naturhist.
Mus. Hamburg, 1898, p. 60 (Yap); Finsch, Das Tierreich, no. 15,
1901, p. 24 (Yap); Matschie, Journ. f. Ornith., 1901, pp. 112, 113
(Yap); Dubois, Syn. Avium, 1, 1902, p. 708 (Uap); Reichenow, Die
Vögel, 2, 1914, p. 469 (Karolinen=Yap); Takatsukasa and Kuroda,
Tori, 1, 1915, p. 64 (Mackenzie=Yap); Kuroda, in Momiyama, Birds
Micronesia, 1922, p. 76 (Yap); Mathews, Syst. Avium
Australasianarum, 2, 1930, p. 700 (Yap); Hand-list Japanese Birds,
3d ed., 1942, p. 192 (Yap).
_Zosterops conspicillata hypolais_ Stresemann, Mitt. Zool. Mus.
Berlin, 17, 1931, p. 227 (Yap); Mayr, Amer. Mus. Novit., no. 1269,
1944, p. 7 (Yap); _idem_, Birds Southwest Pacific, 1945, p. 299
(Yap).
_Zosterops hypolais_ Hand-list Japanese Birds, rev., 1932, p. 173
(Yap).
_Geographic range._--Micronesia: Caroline Islands--Yap.
_Characters._--According to Hartlaub and Finsch (1872:95), "Upper
parts of a pale greyish green, throat and under tail-coverts a
pure but very pale whitish-yellow; breast and abdomen of a mixed
pale grey and pale yellow; wing- and tail-feathers pale blackish,
margined with greenish colour of the back; under wing-coverts and
inner margins of remiges white; eye-ring indistinct; beak fuscous,
the under mandible paler, except at the tip; feet plumbeous."
_Remarks._--No specimen has been examined by me. I am following
Stresemann (1931:227) in placing the Bridled White-eye at Yap as a
subspecies of _Z. conspicillata_. This is one arrangement; the committee
who prepared the Hand-list of Japanese Birds (1942:192) treat this bird
as a separate species. The Japanese probably have more specimens of this
bird than anyone else and may be in a better position to judge its
taxonomic status. Specimens of this white-eye were taken by Fisher in
1946 at Yap. His report (soon to be published) may throw additional
light on the degree of distinctness of _Z. c. hypolais_. On the basis of
published descriptions it is evident that _Z. c. hypolais_ has a few
characters in common with other members of the species.
_Evolutionary history of Zosterops conspicillata._--The small
olive-green and yellow white-eyes of Micronesia have been considered as
belonging to several species by authors in the past. As late as 1930,
Mathews (1930; 700, 706) placed them in four species. Stresemann (1931a:
227) put them all in the species _Z. conspicillata_, an arrangement
which is being followed in this report. It is evident, however, that
these subspecies of _Z. conspicillata_ can be associated into three
groups. The author (1948:73) states that _Z. c. conspicillata_ and _Z.
c. saypani_ have pale chins and throats, light fronto-loral bands,
blackish coloring at the bend of the wings and broad, white orbital
rings. Another group, _Z. c. rotensis_, _Z. c. semperi_, _Z. c.
owstoni_, and _Z. c. takatsukasai_, have bright yellow chins and
throats, matching the rest of the underparts, obscure fronto-loral
bands, which are narrowly tinged with yellow, yellowish coloring at the
bend of the wings, and narrow, white orbital rings. _Z. c. hypolais_
apparently falls into a third group by itself, as indicated by the
published descriptions. There is apparently some variation in the color
of the eyes of these subspecies; they may be either whitish or chestnut
in color. The data are insufficient to determine the significance of
this color character.
_Z. conspicillata_ is restricted to Micronesia and appears to have
little close relationship to other species of the genus. _Z.
conspicillata_ shows little affinity to white-eyes to the north and
northwest of Micronesia belonging to the species _Z. japonica_, of which
representatives are found in the Bonin and Volcano islands. _Z.
conspicillata_ shows greater affinity to species found to the west and
to the south of Micronesia.
It may have colonized Micronesia from the south or southeast
(Polynesia), even though the species is absent at Kusaie; however, _Z.
conspicillata_ shows more relationships to species now living to the
westward and the southwestward, and it probably invaded Micronesia from
some place in that direction. _Z. conspicillata_ differs from species
found in Melanesia and Malaysia chiefly in color of the forehead, lores,
fronto-loral band, crown, nape, breast, abdomen, orbital ring, and bill.
Also there are differences in the breadth of the orbital ring.
_Z. conspicillata_ shows evidence of relationships with _Z. nigrorum_ of
the Philippines and _Z. montanus_ of the Philippines and other parts of
Malaysia. _Z. nigrorum_ resembles _Z. c. semperi_ of Palau in size, but
is brighter yellow-green above with a darker and less curved bill and
brighter underparts. The fronto-loral band and the lores are colored the
same in _Z. nigrorum_ and _Z. c. semperi_. _Z. montanus_ resembles _Z.
conspicillata_ especially in size and in shape of the bill. _Z. lutea
intermedia_ of the Makassar area shows some affinity to _Z.
conspicillata_, although the bill is heavier. The Micronesia species
also bears a close resemblance to _Z. griseotincta_ of the Papuan
region. This is especially true of _Z. c. takatsukasai_ at Ponapé;
however, _Z. griseotincta_ has a heavier and larger bill. _Z. lateralis_
from southern Melanesia and Australia is not very different from _Z.
conspicillata_ aside from its grayish and brownish coloring.
_Z. conspicillata_ probably was derived from an ancestral stock which
came to Micronesia from the Philippine or Moluccan area, rather than
directly from Melanesia. _Z. conspicillata_ seemingly shows the closest
resemblance to _Z. nigrorum_ or to some of its relatives in the
Australo-Moluccan area. The subspecies at Palau, _Z. c. semperi_,
appears to be the connecting link. Whether the form at Yap represents an
independent colonization is not known; such might also be true in the
case of the subspecies at Guam and at Saipan and Tinian. If these are
considered as separate colonizations, then the populations can be
regarded as separate species. Mayr, (in conversation) has pointed out
the affinity of the white-eye at Samoa, _Z. samoensis_, with _Z.
conspicillata_ and suggests that _Z. samoensis_ is derived from the
Micronesian species.
=Zosterops cinerea cinerea= (Kittlitz)