_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)