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

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

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

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

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