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).