Chapter XVII: Part 17

_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)

Micronesian Dusky White-eye

_Drepanis cinerea_ Kittlitz, Kupfertaf. Naturgesch. Vögel, 1, 1832,
p. 6, pl. 8, fig. 2. (Type locality, Ualan = Kusaie.)

_Drepanis cinerea_ Kittlitz, Mém. Acad. Imp. Sci., St.
Pétersbourg, 2, 1835, p. 4, pl. 5 (Ualan); _idem_, Obser. Zool.,
in Lutké, Voy. "Le Séniavine," 3, 1836, p. 285 (Ualan);
Reichenbach, Syn. Avium, 1853, p. 242 (Ualan); Kittlitz, Denkw.
Reise, russ. Amer. Micron. und Kamchat., 1, 1858, p. 367 (Ualan).

_Zosterops cinerea_ Hartlaub, Archiv f. Naturgesch., 18, 1852, p.
131 (Ualan); Gray, Cat. Birds Trop. Is. Pacific Ocean, 1859, p. 16
(Oualan); _idem_, Hand-list Birds, 1, 1869, p. 163 (Caroline =
Kusaie); Hartlaub and Finsch, Proc. Zool. Soc. London, 1872, p. 96
(Ualan); Finsch, Journ. Mus. Godeffroy, 12, 1876, p. 27 (Ualan);
_idem_, Ibis, 1881, pp. 107, 108 (Kuschai); Gadow, Cat. Birds
British Mus., 9, 1884, p. 198 (Kushai); Tristram, Cat. Birds,
1889, p. 210 (Kuschai); Wiglesworth, Abhandl. und Ber. Zool. Mus.
Dresden, no. 6, 1890-1891 (1891), p. 36 (Ualan); Hartert, Kat.
Vogelsamml., Senckenb., 1891, p. 31 (Ualan); Oustalet, Nouv. Arch.
Mus. Hist. Nat. Paris, (3), 7, 1895, p. 208 (Oualan); Finsch, Das
Tierreich, no. 15, 1901, p. 45 (Kusaie); Dubois, Syn. Avium, 1,
1902, p. 713 (Kusaie); Takatsukasa and Kuroda, Tori, 1, 1915, pp.
55, 64 (Kusaie); Wetmore, in Townsend and Wetmore, Bull. Mus.
Comp. Zoöl., 63, 1919, p. 224 (Kusaie); Stresemann, Mitt. Zool.
Mus. Berlin, 17, 1931, p. 230 (Kusaie); Hand-list Japanese Birds,
rev., 1932, p. 173 (Kusaie); Hand-list Japanese Birds, 3d ed.,
1942, p. 192 (Kusaie).

_Dicaeum cinereum_ Hartlaub, Journ. f. Ornith., 1854, p. 168
(Carolinen = Kusaie).

_Zosterops cinereus_ Finsch, Journ. Mus. Godeffroy, 8, 1875, p. 17
(Ualan); idem, Journ. f. Ornith., 1880, pp. 286, 297, 300
(Kuschai); _idem_, Mitth. Ornith. Ver. Wien, 1884, p. 48
(Kuschai).

_Zosterops Kittlitzi_ Finsch, Journ. f. Ornith., 1880, p. 300
(Type locality, Kusaie); Reichenow and Schalow, Journ. f. Ornith.,
1881, p. 94 (Kusaie?).

_Tephras cinereus_ Matschie, Journ. f. Ornith., 1901, pp. 111,
112, 113 (Ualan).

_Tephras cinerea_ Kuroda, in Momiyama, Birds Micronesia, 1922, p.
77 (Kusaie); Mathews, Syst. Avium Australasianarum, 2, 1930, p.
712 (Oualan).

_Zosterops cinerea cinerea_ Mayr, Amer. Mus. Novit., no. 1269,
1944, p. 7 (Kusaie?); _idem_, Birds Southwest Pacific, 1945, p.
300 (Kusaie).

_Geographic range._--Micronesia: Caroline Islands--Kusaie.

_Characters._--Adult: A small, dusky white-eye with upper parts
smoky olivaceous-gray; lores dingy white; auriculars brownish; no
white orbital ring; wing and tail feathers dark brownish-gray with
paler greenish-gray outer edges; underparts pale ashy-gray, chin
lighter, flanks darker; bill black; feet light brown; iris brown.

_Measurements._--Measurements of _Z. cinerea_ are listed in table
51. Males and females have approximately equal measurements.

TABLE 51. MEASUREMENTS OF _Zosterops cinerea_

====================+=====+=========+=========+=============+=========
SUBSPECIES | No. | Wing | Tail | Culmen | Tarsus
--------------------+-----+---------+---------+-------------+---------
_Z. c. cinerea_ | 47 | 63 | 37 | 15.0 | 20
| | (60-65) | (35-39) | (14.0-16.5) | (19-20)
| | | | |
_Z. c. ponapensis_ | 38 | 59 | 38 | 13.5 | 20
| | (57-61) | (36-40) | (13.0-14.5) | (18-21)
| | | | |
_Z. c. finschii_ | 30 | 65 | 43 | 17.5 | 21
| | (63-67) | (40-46) | (16.0-18.5) | (20-23)
--------------------+-----+---------+---------+-------------+---------

_Specimens examined._--Total number, 50 (33 males, 17 females), as
follows: Caroline Islands, USNM--Kusaie, 1 (Feb. 9); AMNH--Kusaie,
49 (Jan., Feb., March).

_Nesting._--Coultas found that approximately one-half of the males
which he obtained in March, 1931, had swollen gonads.

_Molt._--Many of the birds obtained in January and February were
molting, and many of those obtained in March were in fresh
plumage.

_Remarks._--Coultas obtained a large series of these birds at Kusaie in 1931, where he found them to be common.

=Zosterops cinerea ponapensis= Finsch

Micronesian Dusky White-eye

_Zosterops ponapensis_ Finsch, Proc. Zool. Soc. London, 1875
(1876), p. 643. (Type locality, Ponapé.)

_Zosterops ponapensis_ Finsch, Journ. Mus. Godeffroy, 12, 1876,
pp. 17, 27, pl. 2, fig. 1 (Ponapé); _idem_., Proc. Zool. Soc.
London, 1877 (1878), p. 778 (Ponapé); Nehrkorn, Journ. Mus.
Godeffroy, 1879, p. 396 (Ponapé?); Finsch, Journ. f. Ornith.,
1880, pp. 286, 300 (Ponapé); _idem_, Ibis. 1881, pp. 110, 111, 115
(Ponapé); Schmeltz and Krause, Ethnogr. Abth. Mus. Godeffroy,
1881, p. 281 (Ponapé); Finsch, Mitth. Ornith. Ver. Wien, 1884, p.
48 (Ponapé); Gadow, Cat. Birds British Mus., 9, 1884, p. 198
(Ponapé); Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no.
6, 1890-1891 (1891), p. 36 (Ponapé); Bolau, Mitteil. Naturhist.
Mus. Hamburg. 1898, p. 60 (Ponapé); Nehrkorn, Kat. Eiers., 1899,
p. 80 (Ponapé); Finsch, Das Tierreich, no. 15, 1901, p. 46
(Ponapé); Dubois, Syn. Avium, 1, 1902, p. 713 (Ponapé); Reichenow,
Die Vögel, 2, 1914, p. 470 (Ponapé); Takatsukasa and Kuroda, Tori,
1, 1915, pp. 55, 65 (Ponapé); Stresemann, Mitt. Zool. Mus. Berlin,
17, 1931, p. 230 (Ponapè); Yamashina, Tori, 7, 1932, p. 397
(Ponapé); Hand-list Japanese Birds, rev., 1932, p. 173 (Ponapé);
Mayr, Proc. 6th Pacific Sci. Congr., 4, 1941, p. 204 (Ponapé);
Hand-list Japanese Birds, 3d ed., 1942, p. 192 (Ponapé).

_Tephras ponapensis_ Matschie, Journ. f. Ornith., 1901, pp. 111,
112, 113 (Ponapé); Kuroda, in Momiyama, Birds Micronesia, 1922, p.
77 (Ponapé); Mathews, Syst. Avium Australasianarum, 2, 1930, p.
712 (Ponapé).

_Zosterops ponapenensis_ Wetmore, in Townsend and Wetmore, Bull.
Mus. Comp. Zoöl., 63, 1919, p. 224 (Ponapé).

_Zosterops cinerea ponapensis_ Mayr, Amer. Mus. Novit., no. 1269,
1944, p. 7 (Ponapé?); _idem_, Birds Southwest Pacific, 1945, p.
300 (Ponapé).

_Geographic range._--Micronesia: Caroline Islands--Ponapé.

_Characters._--Adult: Resembles adult of _Z. c. cinerea_, but
smaller with upper parts umber-brown, forehead pale gray;
underparts mostly pale gray, sides of breast and abdomen
brownish-buff; under tail-coverts pale buffy-gray.

_Measurements._--Measurements are listed in table 51.

_Specimens examined._--Total number, 47 (28 males, 17 females, 2
unsexed), as follows: Caroline Islands, USNM--Ponapé, 1 (Feb. 11);
AMNH--Ponapé, 46 (Nov., Dec.).

_Nesting._--Yamashina (1931a:397-398) describes two nests of _Z. c.
ponapensis_, each containing one egg. These were taken at Ponapé on
August 4 and 11, 1931. The nests were located 2.5 meters from the
ground. The eggs are light blue and pale greenish-blue in color;
one measures 18.5 by 13.5. He writes, "The nest consists of two
layers, the inner and the outer. The outer layer is made of fine
roots, fibers, leaves and petals, interwoven with a large quantity
of cotton-wool, and the inner layer is made of fibers of fine roots
only." Coultas found that a large number of birds taken in November
had enlarged gonads, especially the males; in December, fewer birds
with swollen gonads were obtained.

_Remarks._--Coultas found this white-eye to be common at Ponapé, when he visited that island in November and December, 1930. He observed the birds in flocks and found them noisy and quarrelsome. They feed in bushes and small trees on seeds and insects. Richards obtained "small large-seeded blackish berries" from the stomach of a female from Ponapé. He found the birds to frequent low altitudes in and about native gardens.

=Zosterops cinerea finschii= (Hartlaub)

Micronesian Dusky White-eye

_Tephras finschii_ Hartlaub, in Hartlaub and Finsch, Proc. Zool.
Soc. London, 1868, p. 6, pl. 3. (Type locality, Pelew Islands.)

_Tephras finschii_ Hartlaub and Finsch, Proc. Zool. Soc. London,
1868, pp. 117, 118 (Pelew Islands).

_Zosterops finschii_ Gray, Hand-list Birds, 1, 1869, p. 164
(Pelew); Gadow, Cat. Birds British Mus., 9, 1884, p. 197 (Pelew);
Bolau, Mitteil. Naturhist. Mus. Hamburg, 1898, p. 60 (Palau).

_Zosterops finschi_ Hartlaub and Finsch, Proc. Zool. Soc. London,
1872, pp. 89, 96 (Pelew); Finsch, Journ. Mus. Godeffroy, 8, 1875,
pp. 4, 17 (Palau); _idem_, Journ. Mus. Godeffroy, 12, 1876, p. 27
(Palau); Giebel, Thes. Ornith., 3, 1877, p. 775 (Pelew); Finsch,
Journ. f. Ornith., 1880, p. 300 (Pelew?); Schmeltz and Krause,
Ethnogr. Abth. Mus. Godeffroy, 1881, p. 407 (Palau); Tristram,
Cat. Birds, 1889, p. 211 (Pelew); Wiglesworth, Abhandl. und Ber.
Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 36 (Pelew);
Finsch, Das Tierreich, no. 15, 1901, p. 45 (Palau); Dubois, Syn.
Avium, 1, 1902, p. 713 (Pelew); Reichenow, Die Vögel, 2, 1914, p.
470 (Palau); Takatsukasa and Kuroda, Tori, 1, 1915, pp. 55, 64
(Pelew); Stresemann, Mitt. Zool. Mus. Berlin, 17, 1931, p. 230
(Palau); Hand-list Japanese Birds, rev., 1932, p. 173 (Palau);
Hand-list Japanese Birds, 3d ed., 1942, p. 192 (Babelthuap,
Koror).

_Tephras finschi_ Matschie, Journ. f. Ornith., 1901, pp. 112, 113
(Palau); Kuroda, in Momiyama, Birds Micronesia, 1922, p. 77
(Pelew); Mathews, Syst. Avium Australasianarum, 2, 1930, p. 712
(Pelew).

_Zosterops cinerea finschi_ Mayr, Birds Southwest Pacific, 1945,
p. 300 (Palau).

_Zosterops cinerea finschii_ Baker, Smithson. Misc. Coll., vol.
107, no. 15, 1948, p. 74 (Peleliu, Garakayo).

_Geographic range._--Micronesia: Palau Islands--Babelthuap, Koror,
Garakayo, Peleliu, Ngabad.

_Characters._--Adult: Resembles adult of _Z. c. cinerea_, but
upper parts mostly browner; wing and tail feathers browner; head
blacker; rump lighter than back; auriculars grayish-brown; lores
dark; sides of head and neck brownish; underparts mostly dark;
chin and throat smoky gray; breast and abdomen more brown less
gray; sides, flanks and under tail-coverts brown. Resembles adult
of _Z. c. ponapensis_, but larger with underparts more buffy;
upper parts darker.

_Measurements._--Measurements are listed in table 51.

_Specimens examined._--Total number, 37 (15 males, 19 females, 3
unsexed), as follows: Palau Islands, USNM--Babelthuap, 1 (Nov.
27)--Koror, 3 (Nov. 4, 5)--Garakayo, 6 (Sept. 18)--Peleliu, 5 (Aug.
27, Sept. 10); AMNH--exact locality not given, 22 (Oct., Nov.,
Dec.).

_Molt._--Many of the specimens of _Z. c. finschii_ taken in the
period from August to December show evidences of molt. Some of the
birds taken in November and in December appear to be in fresh
plumage. All three subspecies of _Z. cinerea_ evidently undergo a
period of molt in the late summer and fall.

_Remarks._--The Micronesian Dusky White-eye of Palau was found on several of the islands of the southern Palaus by the NAMRU2 party in 1945. The bird was observed in flocks of five or more individuals moving rapidly through the foliage of trees and shrubs. It was not found in the dense, undisturbed jungle areas, but rather in second growth vegetation and along the margins of woodlands. At Peleliu, birds were noted in trees and shrubs along the roadways; at Garakayo, birds were seen in low trees near the summits of hills. At Garakayo, _Z. cinerea_ and _Z. conspicillata_ were found in the same areas near the tops of the hills. Both species appeared to be feeding on seeds of the same trees (unidentified but resembling the hibiscus). _Z. cinerea_ was more numerous than _Z. conspicillata_ and appeared (from observations made on September 18, 1945) to be the dominant species and was seen to chase the smaller _Z. conspicillata_ away. Coultas (field notes) found _Z. cinerea_ "fairly common" in 1931 at Palau.

_Evolutionary history of Zosterops cinerea._--The dusky white-eyes of Micronesia were considered as separate species until 1944, when Mayr (1944b:7) treated them as conspecific, stating that the bird at Ponapé has characters intermediate between those at Kusaie and Palau. Earlier, Hartert (1900:3) suggested a close association between _Z. cinerea_ and the species at Truk (now _Rukia ruki_). Mayr concludes that _Z. cinerea_ and _R. ruki_ are not closely related, and points out that the absence of a white orbital ring in _Z. cinerea_ does not necessarily mean that the bird should be considered as belonging to a genus other than _Zosterops_.

The pathway of colonization and the ancestral stock of _Z. cinerea_ are not certainly known. Among the white-eyes of the Polynesian, Melanesian and Malayan areas, there are few kinds which _Z. cinerea_ resembles closely. Mayr (1941b:204) writes that the _Z. cinerea_ at Ponapé was derived from either Polynesia or Papua. I find little in common between _Z. cinerea_ and the species in these areas, and in my opinion _Z. cinerea_ is closest to _Z. atriceps_ of the Moluccas. _Z. atriceps_ has plumage which is part grayish and part brownish. Its underparts resemble those of _Z. c. cinerea_ but are paler gray; crown, neck, and shoulder much like that of _Z. c. ponapensis_ and _Z. c. finschii_; and bill resembling that of _Z. c. cinerea_. _Z. atriceps_ differs by having olive-green coloring on back and wings and yellowish coloring on under side of tail. Thus, it is possible that _Z. cinerea_ invaded Micronesia from the Moluccan region, reaching either Palau or Ponapé initially.

=Rukia palauensis= (Reichenow)

Palau Greater White-eye

_Cleptornis palauensis_ Reichenow, Journ. f. Ornith., 1915, p. 125.
(Type locality, Babeldzuap = Babelthuap, Palauinseln.)

_Megazosterops palauensis_ Stresemann, Ornith. Monatsber., 38,
1930, p. 159 (Baobeltaob); Snouckaert, Alauda (2), 3, 1931, p. 26
(Palau); Stresemann, Mitt. Zool. Mus. Berlin, 17, 1931, p. 235
(Baobel Taob = Babelthuap); Mathews, Ibis, 1931, p. 48 (Palau);
Hand-list Japanese Birds, rev., 1932, p. 172 (Palau); Yamashina,
Tori, 10, 1940, p. 674 (Palau); Hand-list Japanese Birds, 3d ed.,
1942, p. 191 (Babelthuap, Peleliu).

_Rukia palauensis_ Mayr, Amer. Novit., no. 1269, 1944, p. 7
(Palau); _idem_, Birds Southwest Pacific, 1945, pp. 294, 300
(Peliliu); Baker, Smithson. Misc. Coll., vol. 107, no. 15, 1948,
pp. 67, 74 (Peleliu).

_Geographic range._--Micronesia: Palau Islands-Babelthuap, Peleliu.

_Characters._--Adult: A large white-eye with upper parts near
"Saccardo's olive" (some individuals darker brown), head and neck
more olivacious, rump browner; auriculars blackish with pale
yellow streaks; narrow supra-orbital stripe pale olive; orbital
ring indistinct; underparts near "olive lake," chin lighter, under
tail-coverts light yellowish-brown; wing and tail feathers dark
brown, except for tawny outer edges and whitish inner edges;
maxilla horn-color; mandible yellowish to tawny; feet tawny; iris
grayish-brown.

_Measurements._--Measurements of _Rukia_ are listed in table 52.
Measurements of males and females are comparable within the same
species.

TABLE 52. MEASUREMENTS OF _Rukia_

=================+======+=========+=========+=============+=========
SPECIES | No. | Wing | Tail | Culmen | Tarsus
-----------------+------+---------+---------+-------------+---------
_R. palauensis_ | 19 | 80 | 54 | 21.5 | 25
| | (76-84) | (51-57) | (20.0-22.5) | (24-26)
| | | | |
_R. ruki_ | 8 | 81 | 52 | 21.5 | 23
| | (76-85) | (51-52) | (20.0-23.0) | (22-24)
| | | | |
_R. sanfordi_ | 18 | 70 | 44 | 23.0 | 21
| | (67-71) | (41-47) | (22.0-24.0) | (20-22)
-----------------+------+---------+---------+-------------+---------

_Specimens examined._--Total number, 21 (12 males, 9 females), as
follows: Palau Islands, USNM--Peleliu, 11 (Aug. 27, 29, 30, Sept.
4, 5, 6, 7, Dec. 4, 5); AMNH--Peleliu?, 10 (Dec.).

_Molt._--Specimens taken in August and September are in worn
plumage, a few individuals show evidence of molt. Specimens taken
in December are in fresh plumage, although two or three individuals
are in the final stages of molt. This places the period of molt as
September, October, and November. Nesting evidently occurs in the
summer; one male taken on August 27, 1945, had enlarged gonads.

_Remarks._--The Palau Greater White-eye was described under the generic name _Cleptornis_ by Reichenow. This generic allocation was not followed by subsequent authors; Stresemann proposed the generic name _Megazosterops_ in 1930, and Mayr (1944b:7) placed this white-eye in the genus _Rukia_ along with other large white-eyes from Micronesia. In employing this name, Mayr writes, "The generic names _Rukia_ (for _ruki_) and _Kubaryum_ (for _oleaginea_) were published simultaneously in the same publication. As first reviser I select the name _Rukia_, which not only is shorter but is also based on a species which I have been able to examine."

_R. palauensis_ is recorded from Babelthuap and Peleliu of the Palau Islands. In 1931, Coultas found the birds only at the island of Peleliu, where he obtained nine specimens from a flock. In 1940, Yamashina (1940:674) writes that it is a very rare species at Palau. Marshall (1949:219) found the bird at Peleliu but at no other islands visited. In 1945, the NAMRU2 party obtained eight specimens at Peleliu from two localities on the eastern side of the island in jungle areas relatively undisturbed by war activities. The birds were fairly common in the brush and vines of the jungle undergrowth at these two areas. There were no flocks seen; usually singles or pairs were noted. The bird bears a striking resemblance to _Psamathia annae_, which lives in the same environment and has a somewhat similar coloration, shape and posture. These two birds probably have undergone a parallel development. Competition between the two was not noted. _Psamathia_ is evidently less restricted in its distribution.

_R. palauensis_ has a restricted distribution in the Palau Islands, as indicated by the observations of Coultas, the Japanese and the NAMRU2 party. The disturbance resulting from the war activities has undoubtedly influenced the population and restricted further the preferred habitat of this white-eye, especially at Peleliu.

=Rukia oleaginea= (Hartlaub and Finsch)

Yap Greater White-eye

_Zosterops oleaginea_ Hartlaub and Finsch, Proc. Zool. Soc. London,
1872, p. 95. (Type locality, Uap.)

_Zosterops oleaginea_ Gräffe, Journ. Mus. Godeffroy, 2, 1873, p.
122 (Yap); Gadow, Cat. Birds British Mus., 9, 1884, p. 187 (Yap);
Finsch, Das Tierreich, no. 15, 1901, p. 24 (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); Stresemann, Mitt. Zool. Mus. Berlin, 17, 1931, p. 230
(Yap); Hand-list Japanese Birds, rev., 1932, p. 173 (Yap);
Hand-list Japanese Birds, 3d ed., 1942, p. 192 (Yap).

_Zosterops oleaginea_ Giebel, Thes. Ornith., 3, 1877, p. 777
(Mackenzie); Schmeltz and Krause, Ethnogr. Abth. Mus. Godeffroy,
1881, p. 391 (Yap); 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).

_Tephras oleaginea_ Matschie, Journ. f. Ornith., 1901, pp. 112,
113 (Yap).

_Kubaryum oleaginus_ Momiyama, Birds Micronesia, 1922, p. 1 (Yap);
Kuroda, in Momiyama, Birds Micronesia, 1922, p. 77 (Yap).

_Kubaryum oleagineum_ Mathews, Syst. Avium Australasianarum, 2,
1930, p. 712 (Yap).

_Rukia oleaginea_ Mayr, Amer. Mus. Novit., no. 1269, 1944, p. 7
(Yap); _idem_, Birds Southwest Pacific, 1945, p. 300 (Yap).

_Geographic range._--Micronesia: Caroline Islands--Yap.

_Characters._--According to Hartlaub and Finsch (1872:95),
"General colour a deep oil-green, with a decided fulvous hue;
underparts a little paler, and a little more yellowish; eye-ring
satin-white; ears blackish; upper and under tail coverts with a
slight rufous tinge; wing- and tail-feathers blackish, with
oil-green margins; under wing-coverts whitish-grey; beak fulvous,
under mandible, except at the tip, yellowish; feet pale, probably
yellow; iris reddish white."

_Remarks._--No specimens of _R. oleaginea_ have been examined by me, and I am following Mayr (1944b:7) in including it with the other large white-eyes of Micronesia in the genus _Rukia_.

=Rukia ruki= (Hartert)

Truk Greater White-eye

_Tephras ruki_ Hartert, Bull. British Ornith. Club, 7, 1897, p. 5.
(Type locality, Ruk.)

_Tephras ruki_ Hartert, Ibis, 1898, p. 144 (Ruk); _idem_, Novit.
Zool., 7, 1900, p. 3 (Ruk); Matschie, Journ. f. Ornith., 1901, pp.
111, 112, 113 (Ruck); Mathews, Syst. Avium Australasianarum, 2,
1930, p. 712 (Ruk).

_Zosterops ruki_ Finsch, Das Tierreich, no. 15, 1901, p. 46 (Ruk);
Dubois, Syn. Avium, 1, 1902, p. 713 (Ruk); Reichenow, Die Vögel,
2, 1914, p. 470 (Ruk); Takatsukasa and Kuroda, Tori, 1, 1915, p.
64 (Ruk); Stresemann, Mitt. Zool. Mus. Berlin, 17, 1931, p. 230
(Truk); Hand-list Japanese Birds, rev., 1932, pp. 172 (Truk);
Hand-list Japanese Birds, 3d ed., 1942, p. 191 (Truk).

_Rukia ruki_ Momiyama, Birds Micronesia, 1922, p. 2 (Ruk); Kuroda,
in Momiyama, Birds Micronesia, 1922, p. 78 (Ruk); Mayr, Amer. Mus.
Novit., no. 1269, 1944, p. 7 (Truk); _idem_, Birds Southwest
Pacific, 1945, p. 301 (Truk).

_Geographic range._--Micronesia: Caroline Islands--Truk.

_Characters._--According to Hartert (1897:5), "Entirely
sepia-brown, the inner webs of the remiges and under wing-coverts
lighter, inclining to whitish; the primaries darker, the outer
webs bordered with the same colour as the back. Bill black; iris
red; tarsi and feet orange-rufous; claws mouse-brown." _R. ruki_
may be distinguished from other species of _Rukia_ by its dark
olive-brown coloring.

_Measurements._--Measurements are listed in table 52.

_Specimens examined._--Total number, 7 (4 males, 2 females, 1
unsexed), from Caroline Islands, AMNH--Truk (Nov., Dec.).

_Remarks._--This white-eye was first obtained by Owston's collectors in 1895 at Truk. Hartert (1900:3) writes, "It is most peculiar that the late J. Kubary, who was an excellent collector, and who spent more than fourteen months on Ruk, did not obtain this bird. It is probably not numerous, and occurs only on a certain secluded spot not visited by Kubary." In like manner, _R. palauensis_ was not described from Palau until 1915, although several collectors had visited the island at previous times. Hartert included the Truk Greater White-eye in the genus _Tephras_ of Hartlaub. Later, Momiyama (1922:2) made this bird the type for his new genus _Rukia_, in which Mayr has placed all of the large white-eyes of Micronesia.

=Rukia sanfordi= (Mayr)

Ponapé Greater White-eye

_Rhamphozosterops sanfordi_ Mayr, Ornith. Monatsber., 39, 1931
[mailing date, Nov. 4, 1931, _ex_ Mayr, 1944b:8], p. 182. (Type
locality, Ponapé.)

_Cinnyrorhyncha longirostra_ Takatsukasa and Yamashina, Dobutsu.
Zasshi, 43, 1931 [printed date, Oct. 15, 1931, but mailing date
for extra-Japanese recipients, Nov. 23, 1931, _ex_ Mayr, 1944b:8],
p. 599. (Type locality, Ponapé); Hand-list Japanese Birds, rev.,
1932, p. 172 (Ponapé); Hand-list Japanese Birds, 3d ed., 1942, p.
191 (Ponapé).

_Cinnyrorhyncha longirostris_ Mathews, Ibis, 1933, p. 94 (Ponapé).

_Rhamphozosterops sanfordi_ Mayr, Proc. 6th Pacific Sci. Congr.,
4, 1941, p. 204 (Ponapé).

_Rukia sanfordi_ Mayr, Amer. Mus. Novit., no. 1269, 1944, p. 7
(Ponapé); _idem_, Birds Southwest Pacific, 1945, p. 301 (Ponapé).

_Geographic range._--Micronesia: Caroline Islands--Ponapé.

_Characters._--Adult: upper parts buffy-olive, head greenish, rump
and upper tail-coverts buffy-brown; wing and tail feathers dark
brown, outer edges yellowish-olive; underparts grayish-buff, chin
and throat faintly washed with greenish-yellow; under tail-coverts
darker; bill long, curved and brownish-black, base of mandible
paler; feet yellowish; iris chestnut. _R. sanfordi_ is
distinguished from other species of _Rukia_ by its smaller size,
its paler coloration and its longer and more curved bill.

_Measurements._--Measurements are listed in table 52.

_Specimens examined._--Total number, 18 (12 males, 6 females), from
Caroline Islands, AMNH--Ponapé (Nov., Dec.).

_Remarks._--Coultas obtained this white-eye at Ponapé in 1931; he writes (field notes) that it is "a very rare bird on Ponapé. I found them at one tree, a sort of a gum-tree, at about 2,000 feet, where they were collecting from the flowers of the tree. I was attracted by their deep-throated sibilation that is uttered while feeding. They were not in the least disturbed by the noise of the gun and remained long enough for me to collect a substantial series. One old man, who lives not far from the tree, was the only one I could find who knew the bird." Six males and one female taken in December had swollen gonads. Richards found this bird to be rare at Ponapé in 1947-1948. He writes (field notes) that the bird was seen twice (he obtained one male), once in deep forest at about 700 feet and once at the summit of Jokaj at 900 feet. He observed a group of three birds "wildly and loudly chasing one another from tree to tree." The male obtained had yellowish sap adhering to its bill.

The Ponapé Greater White-eye has an appearance very much like that of some of the honey-eaters. Takatsukasa and Yamashina (1931c:599) write, "General appearance very much like either _Cinnyris_ or _Myzomela_, but it differs from them by its very small first primary, which is far shorter than the primary coverts, and also the smooth cutting edge of the bill, though the bill is similarly shaped as to that of _Cinnyris_. These characteristics show that this bird belongs to _Zosteropidae_ but not _Nectarinidae_ or _Meliphagidae_."

Mayr and the Japanese workers, Takatsukasa and Yamashina, published descriptions of this white-eye at Ponapé almost simultaneously. Mayr (1944b:8) contends that his name, _Rhamphozosterops sanfordi_, is valid because the mailing date of the journal (Ornithologische Monatsberichte) in which _R. sanfordi_ was proposed was November 4, 1931, while his investigations show that the earliest mailing date to European and American ornithologists and libraries of the issue of Dobutsugaku Zasshi in which the name _Cinnyrorhyncha longirostra_, proposed by Takatsukasa and Yamashina, appeared was November 23, 1931. Mayr (1944b:8) points out that Japanese friends of the authors of the name _C. longirostra_ assert that they saw copies of the description [inferentially printed copies] prior to November 23, 1931. These Japanese, as far as is known, have not claimed that they saw copies before November 4, 1931, and Mayr's conclusion that his name, _R. sanfordi_, has priority is here accepted. If the name _C. longirostra_ Takatsukasa and Yamashina appeared in printed form and if copies, in requisite number, were distributed to specialists or libraries in Japan, or anywhere else, on or before November 3, 1931, the name _C. longirostris_ has priority over _R. sanfordi_.

_Evolutionary history of Rukia in Micronesia._--There is little known concerning the status of the large white-eyes of Micronesia. Most of them were not found by the earlier collectors and are at present reported to be rare or restricted in their distribution. Little is known concerning the food preferences and nesting activities of the birds and also whether they are actually in danger of extermination or whether their populations are normally as low as have been reported. Originally described under four different generic names, they are now considered as belonging in a single genus, _Rukia_.

I have compared specimens of _Rukia_ with those of other members of the family Zosteropidae found in the Pacific area. _Rukia_ is apparently not closely related to _Z. conspicillata_ and _Z. cinerea_ of Micronesia but has been derived from a different source or sources. The author has compared _Rukia_ with the genera _Zosterops_, _Woodfordia_, _Hypocryptadius_, _Apoia_, _Chlorocharis_, _Pseudozosterops_, and _Tephrozosterops_. Results of these comparisons indicate that large and well-differentiated white-eyes are found on a number of the islands of Oceania. These white-eyes include _Woodfordia_, _Rukia_, _Zosterops inornata_, _Z. albogularis_, _Z. tenuirostris_, and _Z. strenua_. These birds are all large, have large bills (either longer or stouter or both), large and long tarsi, and often short and rounded wings. _Rukia_ apparently has undergone a differentiation which parallels that which has taken place in these other white-eyes, but there is no evidence of a close relationship between these birds and _Rukia_. There are some resemblances between _Rukia_ and _Woodfordia superciliosa_ of Rennell Island; _W. superciliosa_ is the same size and has a bill somewhat similar to that of _R. ruki_ and a coloration not very different from that of _R. sanfordi_. _R. ruki_ and _R. sanfordi_ may have been derived originally from a common ancestral stock in Melanesia, with subsequent isolation on small islands for considerable time where differentiation took place. _Rukia_ also shows some resemblance to the genus _Apoia_, especially to _A. pinaiae_ of Ceram. There is also a possibility that the large white-eyes of Micronesia are merely highly modified species of the genus _Zosterops_; this has been suggested by Mayr (1944b:7). It is my opinion that _Rukia_ is a valid genus and is as much different from the genus _Zosterops_ (or more so) than other recognized genera of large white-eyes (_Woodfordia_ and _Apoia_). There is also the strong possibility that the large white-eyes of Micronesia have been derived from more than one source (and are falsely united in one genus); however, it is my feeling that they represent a single colonization, which successfully established itself at four islands and evolved into four divergent species. Possibly _R. oleaginea_ is the least specialized and is closest to the ancestral stock; however, this supposition is based on study of the original description and on a colored plate of the bird in a paper by Kuroda (1922b:pl. 7, fig. 4).

In summary, it seems that the large Micronesian white-eyes of the genus _Rukia_ came originally from Melanesia. Possibly they came from Malaysia. Probably the birds have been derived from a single ancestral stock, that became established at four islands of Micronesia and became differentiated along diverse lines, so much so that some ornithologists have considered them as belonging to separate endemic genera.

=Erythrura trichroa trichroa= (Kittlitz)

Blue-faced Parrot-finch

_Fringilla trichroa_ Kittlitz, Mém. Acad. Imp. Sci. St.
Pétersbourg, 2, 1835, p. 8, pl. 10. (Type locality, Ualan =
Kusaie.)

_Fringilla trichroa_ Kittlitz, Obser. Zool., in Lutké, Voy. "Le
Séniavine," 3, 1836, p. 285 (Ualan); _idem_, Denk. Reise russ.
Amer. Micron. und Kamchat., 2, 1858, p. 38 (Ualan).

_Estrelda trichroa_ Gray, Genera Birds, 2, 1849, p. 369 (Kusaie?);
Gray, Cat. Birds Trop. Is. Pacific Ocean, 1859, p. 27 (Oualan).

_Erythrura trichroa_ Bonaparte, Consp. Avium, 1, 1850, p. 457
(Ualan); Hartlaub, Archiv f. Naturgesch., 18, 1852, p. 133
(Carolinen = Kusaie); _idem_, Journ. f. Ornith., 1854, p. 168
(Carolinen = Kusaie); Gray, Hand-list Birds, 2, 1870, p. 58
(Ualan); Giebel, Thes. Ornith., 2, 1875, p. 118 (Carolinen =
Ualan); Finsch, Journ. Mus. Godeffroy, 12, 1876, p. 36 (Ualan);
_idem_ (part), Journ. f. Ornith., 1880, pp. 290, 297, 302
(Kusaie); _idem_ (part), Ibis, 1881, pp. 104, 108 (Kuschai);
Salvadori (part), Ornith. Papuasia, 2, 1881, p. 442 (Carolinis =
Kusaie?); Schmeltz and Krause (part), Ethnogr. Abth. Mus.
Godeffroy, 1881, p. 281 (Kusaie); Sclater (part), Ibis, 1881, p.
545 (Ualan); Sharpe (part), Cat. Birds British Mus., 13, 1890, p.
385 (Carolines = Kusaie); Wiglesworth (part), Abhandl. und Ber.
Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 42 (Ualan);
Matschie (part), Journ. f. Ornith., 1901, p. 112 (Ualan); Dubois
(part), Syn. Avium, 1, 1902, pp. 583 (Carolines = Kusaie);
Takatsukasa and Kuroda (part), Tori, 1, 1915, p. 64 (Kusaie).

_Erythrura kittlitzi_ Bonaparte, Consp. Avium, 1, 1850, p. 457
(_ex_ Bonaparte MSS.) (Type locality, Ualan); Gray, Hand-list
Birds, 2, 1870, p. 58 (Caroline Islands = Kusaie).

_Erythrura trichros trichros_ Hartert (part), Novit. Zool., 7,
1900, p. 6 (Kusaie); Kuroda (part), in Momiyama, Birds Micronesia,
1922, pp. 27, 29, 78 (Kusaie); Mayr (part), Amer. Mus. Novit., no.
489, 1931, p. 4 (Kusaie); Takatsukasa and Yamashina, Tori, 7,
1931, p. 110 (Kusaie); Hand-list Japanese Birds, rev., 1932, p.
170 (Kusaie); Hand-list Japanese Birds, 3d ed., 1942, p. 189
(Kusaie); Mayr, Birds Southwest Pacific, 1945, p. 302 (Kusaie).

_Chloromunia trichroa trichroa_ Mathews (part), Syst. Avium
Australasianarum, 2, 1930, p. 840 (Ualan).

_Geographic range._--Micronesia: Caroline Islands--Kusaie.

_Characters._--Adult: A small finch with thick, stout bill; head,
neck, back, and scapulars between "parrot green" and "grass
green"; forehead, orbital area, auriculars, and malar area bluish;
sides of neck green tinged with yellowish; edge of forehead and
lores blackish; wing-coverts and outer margins of wings
yellowish-green; underparts like back but paler green; rump, upper
tail-coverts and outer edges of tail feathers near "Pompeian red";
wing and tail feathers mostly brownish; bend of wing greenish;
under wing-coverts brownish; axillaries buffy tinged with
greenish; bill black; feet light yellowish-brown; iris brown.
Adult female duller than male.

Immature: Resembles adult, but lacks bluish coloring on sides of
head and on forehead; underparts washed with buffy brown; rump and
tail duller carmine.

_Measurements._--Measurements are listed in table 53.

_Specimens examined._--Total number, 14 (12 males, 2 females), from
Caroline Islands, AMNH--Kusaie (Feb., March, April).

_Molt._--Specimens taken in February and March have mostly new
feathers, molt having been almost completed when obtained.

_Remarks._--Kittlitz was the first person to describe the Blue-faced Parrot-finch; he found it at Kusaie when he visited the island in the winter of 1827-28. Later, it was found to have an extensive range in Micronesia, Melanesia, northern Australia, Celebes, and the Moluccas. This small finch may be kept as a pet in a cage by native peoples, but as far as I know there is no evidence that the bird has been introduced to island areas as a result of this practice.

TABLE 53. MEASUREMENTS OF _Erythrura trichroa_ IN MICRONESIA

=====================+=====+=========+=========+=============+=========
SUBSPECIES | No. | Wing | Tail | Culmen | Tarsus
---------------------+-----+---------+---------+-------------+---------
_E. t. trichroa_ | 6 | 58 | 46 | 13.0 | 17
| | (57-59) | (43-48) | (12.5-13.5) | (16-17)
| | | | |
_E.t. clara_ | 29 | 59 | 45 | 13.5 | 17
| | (57-62) | (41-50) | (13.0-14.5) | (17-18)
| | | | |
_E. t. pelewensis_* | 1 | 61.5 | 51 | 13.5 | 18
---------------------+-----+---------+---------+-------------+---------

* Kuroda (1922:28).

Coultas observed the finch at Kusaie in 1931; he wrote (field notes) that it is a common bird but difficult to obtain. He found it in most parts of the island and at all elevations; the bird appeared to prefer dense underbrush of the jungle or marginal vegetation. He found no evidence of breeding activity in February, March or April.

=Erythrura trichroa clara= Takatsukasa and Yamashina

Blue-faced Parrot-finch

_Erythrura trichroa clara_ Takatsukasa and Yamashina, Tori, 7,
1931, p. 110. (Type locality, Ruk Island.)

_Erythrura trichroa_ Finsch (part), Journ. f. Ornith., 1880, p.
290 (Ponapé, Hügeln = Truk); _idem_, Proc. Zool. Soc. London,
1880, p. 576 (Ruk); _idem_ (part), Ibis, 1881, pp. 104, 110, 112,
115 (Ponapé); Schmeltz and Krause (part), Ethnogr. Abth. Mus.
Godeffroy, 1881, p. 353 (Ruk); Salvadori (part), Ornith. Papuasia,
2, 1881, p. 442 (Ponapé); Sclater (part), Ibis, 1881, p. 545
(Ponapé, Ruk); Sharpe (part), Cat. Birds British Mus., 13, 1890,
p. 385 (Carolines = Truk, Ponapé); Wiglesworth (part), Abhandl.
und Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 42
(Ponapé, Ruk); Nehrkorn, Kat. Eiers, 1899, p. 122 (Ruk); Matschie
(part), Journ. f. Ornith., 1901, p. 112 (Ruk, Ponapé); Dubois
(part), Syn. Avium, 1, 1902, p. 583 (Carolines = Ponapé);
Takatsukasa and Kuroda (part), Tori, 1, 1915, pp. 55, 64 (Ponapé);
Mayr, Proc. 6th Pacific Sci. Congr., 4, 1941, p. 204 (Ponapé).

_Erythrura trichroa trichroa_ Hartert (part), Novit. Zool., 7,
1900, p. 6 (Ruk, Ponapé); Kuroda (part), in Momiyama, Birds
Micronesia, 1922, pp. 27, 28, 29, 78 (Ponapé, Ruk); Mayr (part),
Amer. Mus., Novit., no. 489, 1931, p. 4 (Ponapé, Ruk).

_Chloromunia trichroa_ Mathews, Birds Australia, 12, 1925, p. 208
(Ruk).

_Chloromunia trichroa trichroa_ Mathews (part), Syst. Avium
Australasianarum, 2, 1930, p. 840 (Carolines = Truk, Ponapé).

_Erythrura trichroa clara_ Hand-list Japanese Birds, rev., 1932,
p. 170 (Truk, Ponapé); Hand-list Japanese Birds, 3d ed., 1942, p.
189 (Truk, Ponapé); Mayr, Birds Southwest Pacific, 1945, p. 302
(Truk, Ponapé); Baker, Smithson. Misc. Coll., vol. 107, no. 15,
1948, p. 74 (Truk).

_Lobospingus trichroa clara_ Mathews, Ibis, 1933, p. 96 (Ruk,
Ponapé).

_Geographic range._--Micronesia: Caroline Islands--Truk, Ponapé,
Lukunor?

_Characters._--Adult: Resembles adult of _E. t. trichroa_, but
slightly larger with underparts more yellowish and less greenish;
blue on head slightly paler; sides of neck tinged more strongly
with yellowish. Birds from Ponapé are slightly paler than those
from Truk.

_Measurements._--Measurements are listed in table 53. Birds from
Ponapé and Truk differ but little in measurements.

_Specimens examined._--Total number, 39 (22 males, 16 females, 1
unsexed), as follows: Caroline Islands, USNM--Truk, 2 (May 5,
Dec.); AMNH--Truk, 15 (March, June, Nov.)--Ponapé, 22 (Dec.).

_Molt._--Birds taken in March and June are not in molt. Some of the
specimens obtained in November and December are in molt.

_Remarks._--The differences between _E. t. trichroa_ at Kusaie and _E. t. clara_ at Ponapé and Truk are slight. Takatsukasa and Yamashina (1931d:110) separate _E. t. clara_ from _E. t. trichroa_ of Kusaie on the basis of a paler blue coloring on head, body more yellowish green and sides of neck more distinctly golden-yellow.

Coultas obtained specimens at Ponapé in 1930 and reports (field notes) that the bird occurs in the extensive grassland areas of the island but that the numbers are small. He estimates the population to be less than 100 individuals. He learned that the Japanese had trapped them for shipment to Japan as caged birds. Coultas writes that the finch at Ponapé "is very shy and flies readily when he is disturbed. As soon as a call of alarm is uttered the whole flock flies up from the ground and heads for the true forest where they will hide. They will also work along in the grass, and make a getaway. The bird has a little hissing sybilation that it utters when on the wing." He found the bird in flocks of 3 to 20; immatures were frequently found alone.

McElroy of the NAMRU2 party obtained a female at Moen Island in the Truk Atoll in December, 1945. He found small flocks of these birds in dense vegetation along streams.

=Erythrura trichroa pelewensis= Kuroda

Blue-faced Parrot-finch

_Erythrura trichroa pelewensis_ Kuroda, in Momiyama, Birds
Micronesia, 1922, p. 27. (Type locality, Pelew Islands).

_Erythrura trichroa pelewensis_ Kuroda, Ibis, 1927, p. 692
(Pelew); Mayr. Amer. Mus. Novit., no. 489, 1931, p. 4 (Pelew);
Hand-list Japanese Birds, rev., 1932, p. 171 (Palau); Hand-list
Japanese Birds, 3d ed., 1942, p. 189 (Babelthuap); Mayr, Birds
Southwest Pacific, 1945, p. 301 (Palau).

_Chloromunia trichroa pelewensis_ Mathews, Syst. Avium
Australasianarum, 2, 1930, p. 840 (Pelew).

_Geographic range._--Micronesia: Palau Islands--Babelthuap.

_Characters._--Kuroda (1922a:27) describes the bird as follows,
"Resembles _E. trichroa_ (Kittlitz) from Carolines (the type from
Kusaie), but distinguishable from it by the bill being much
thicker and stouter, by the chin being tinged with blue, by the
under-parts being paler throughout and somewhat tinged with
bluish, by the rump and upper tail-coverts being bright crimson
instead of dull crimson, by the central tail-feathers brownish red
instead of dull crimson, by the distinct shafts of central
tail-feathers and by longer wing and tail."

_Measurements._--The measurements by Kuroda of a single specimen
are listed in table 53.

_Remarks._--Only one specimen of this subspecies is known. The NAMRU2 party did not obtain any record of it in the southern Palaus in 1945. If still present in the islands, it may be confined to the higher forested areas of Babelthuap.

_Evolutionary history of Erythrura trichroa in Micronesia._--The Blue-faced Parrot-finch has been recorded from Kusaie, Ponapé, Truk and Palau, which are all "high" islands of southern Micronesia. This bird belongs to a species which occurs in Melanesia, northern Australia, Celebes, and the Moluccas. Stresemann (1940:40) points out the interesting observation that this species ranges only east of Wallace's Line. Mayr (1931c:1-10) has reviewed the parrot-finches of the genus _Erythrura_ and places _E. trichroa_ in the subgenus _Erythrura_, noting that _E. t. cyaneifrons_ from Banks and the New Hebrides is similar to the subspecies found in Micronesia. As a group the subspecies of _E. trichroa_ are very similar, but the populations in Micronesia appear closest to subspecies from the Solomons, Admiralty Islands and possibly to _E. t. modesta_ from the Moluccas, which appears to indicate that Micronesia was invaded from the south or from the southwest via the Moluccas. Whether the little known subspecies at Palau represents an independent invader from the Moluccas is uncertain.

=Lonchura nigerrima minor= (Yamashina)

Black-breasted Weaver-finch

_Munia (Donacola) hunsteini minor_ Yamashina, in Takatsukasa and
Yamashina, Dobutsu. Zasshi, 43, 1931, p. 600. (Type locality,
Ponapé.)

_Lonchura hunsteini minor_ Hand-list Japanese Birds, rev., 1932,
p. 171 (Ponapé, Truk); Hand-list Japanese Birds, 3d ed., 1942, p.
190 (Ponapé, Truk).

_Donacola hunsteini minor_ Mathews, Ibis, 1933, p. 95 (Ponapé).

_Lonchura nigerrima minor_ Mayr, Birds Southwest Pacific, 1945, p.
301 (Ponapé, ?Truk).

_Geographic range._--Micronesia: Caroline Islands--Ponapé, Truk?

_Characters._--Yamashina in Takatsukasa and Yamashina (1931c:600)
characterizes this subspecies as similar to _M. hunsteini_ from
New Ireland, but smaller; the wing of the adult of the bird from
Ponapé is from 46 to 49 mm, instead of 50-51 mm. as in the New
Ireland bird. Moreover the crown and nape are white instead of
pearl gray.

_Remarks._--Little is known concerning this subspecies named by Yamashina at Ponapé. No specimens have been seen by me. Richards obtained one male at Ponapé in 1947-1948. He found the birds in large flocks.

=Lonchura punctulata cabanisi= (Sharpe)

Philippine Nutmeg Mannikin

_Munia cabanisi_ Sharpe, Cat. Birds British Mus., 13, 1890, p. 353.
(Type locality, Luzon.)

_Munia punctulata cabanisi_ Kuroda, in Momiyama, Birds Micronesia,
1922, p. 78 (Yap).

_Lonchura punctulata cabanisi_ Yamashina, Tori, 7, 1932, p. 395
(Yap); Hand-list Japanese Birds, rev., 1932, p. 171 (Yap);
Hand-list Japanese Birds, 3d ed., 1942, p. 189 (Yap).

_Geographic range._--Philippine Islands and Micronesia. In
Micronesia: Palau Islands; Caroline Islands--Yap.

_Characters._--A small finch with upper parts light grayish-brown,
feathers with white shafts producing a streaked appearance; lores,
anterior part of auriculars, malar region, and feathers of chin
and throat chocolate-brown with faint white shafts; breast and
sides mottled white and dark brown, middle of abdomen and under
tail-coverts pale buffy-white, wings brown with lighter edges,
under wing dark with lighter coverts; upper tail-coverts and
middle tail feathers dark olive, outer tail feathers colored like
wings; bill heavy and black; feet dark brown.

_Remarks._--The Philippine Nutmeg Mannikin is a resident on the island of Yap. Yamashina (1932a:395) records a nest containing one egg taken there on May 15, 1932. Marshall (1949:221) records this bird at Palau on November 6 and December 2, 1945. Whether this bird was introduced to Yap and Palau by man or whether it reached there by independent invasion is unknown.

SUMMARY AND CONCLUSION

The avifauna of Micronesia consists of 206 kinds of birds belonging to 37 families and 91 genera. Of these, 30 kinds are sea birds, 29 kinds are migratory shore birds, and 146 kinds are land and freshwater birds. Of the 30 sea birds, 18 kinds are resident; of the 147 land and fresh-water birds, 104 kinds are resident and 6 kinds have been introduced by man. There are no resident shore birds in Micronesia. The following conclusions can be drawn from this study:

1. The islands of Micronesia are oceanic islands and were seemingly formed independently of any present day continental land mass. Terrestrial organisms have reached these islands by "over-water dispersal." The avifauna of Micronesia has been received from the following sources: Polynesia, Melanesia, the Moluccas, Celebes, Phillipines, and Palearctica (see figure 8).

2. Oceanic birds are among the oldest forms of bird life inhabiting Micronesia. The presence of elevated islands containing phosphate, resulting from the deposition of guano by oceanic birds, is some indication of the length of time during which these birds have been present. In number of individuals, the oceanic birds inhabiting the inshore zone are more numerous than those inhabiting the offshore and pelagic zones, although twelve of the eighteen resident kinds of oceanic birds prefer the offshore and pelagic zones. Most of the species of oceanic birds resident in Micronesia are circumtropical in distribution; no residents are known in Micronesia which have been derived from Palearctica or the North Pacific. Micronesia has no endemic oceanic birds.

3. On the migratory flights, shore birds reach Micronesia along three distinct flyways, which in this report are named the Asiatic-Palauan Flyway, the Japanese-Marianan Flyway, and the Nearctic-Hawaiian Flyway (see figure 7). The shore birds began to utilize the Pacific islands as wintering grounds by gradually spreading from the Eastern Hemisphere rather than from the Western Hemisphere.

4. More than half (52 percent) of the land birds and fresh-water birds in Micronesia were derived directly from ancestral stocks in Melanesia. The areas of the Moluccas and of Celebes (Malaysia) supplied 21 percent of the birds; the Philippines, 10 percent; Polynesia, 9 percent; and Palearctica, 8 percent. Results of this study show that there may have been only 46 actual colonizations of Micronesia by birds from other areas, and that many of the large number of endemics present have been the result of secondary colonizations within the islands of Micronesia. It is concluded that Micronesia, except for the Marshall Islands, has a much closer affinity to Melanesia than to any other area as regards avifauna. The Marshall Islands may be regarded as a part of the Polynesian Subregion from the viewpoint of avian zoogeography.

5. Endemism in the land birds and fresh-water birds of Micronesia is extreme. Of 104 native, resident birds, 97 (93.5 percent) have become differentiated and can be separated taxonomically from related forms. In Micronesia, there are 5 endemic genera, 31 endemic species, and 76 endemic subspecies. The families containing the greatest number of endemic forms are Muscicapidae (14), Zosteropidae (14), Columbidae (13), and Sturnidae (9).

6. It is concluded that some of the more important factors controlling the dispersal of the bird life to Micronesia are the direction and the intensity of the winds, the small size of the islands, the isolation of the islands (especially those "high" islands), and the insular climates, which appear to favor colonists from tropical homes rather than those from Palearctic homes.

7. The factors most important in the process of differentiation of birds in the islands of Micronesia are isolation, paucity in numbers of individuals, freedom from predation, absence (and presence) of interspecific and intraspecific strife, and nutrition. The importance of the "dilution" factor is discussed, and the possibility of cross-breeding between different kinds of birds is considered. It is concluded that genetic change altering the phenotypic expression of avian characteristics is no more apt to occur in insular populations than in continental populations, but such changes have a greater chance of being perpetuated in insular populations.

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