Characters.—According to Sharpe (1890:137), "Shining black; each feather with a glossy margin, varying from steel-green to purplish red; bill and feet black (Kittlitz)."
Remarks.—Kittlitz obtained two specimens of a unique starling at Kusaie when he visited the island in December and January, 1827-'28. He named the birds as new and deposited the specimens in the museum in St. Petersburg. The bird has not been found at Kusaie since that time. Sharpe (1890:137-138, footnote) writes "This species I have never seen, and Dr. Finsch did not meet with it during his visit to Kuschai. He writes to me:—'It no doubt exists on Kuschai, just as it did when Kittlitz visited the island. Nobody has reached the mountains in the interior since Kittlitz's time; and it is strictly a mountain bird.'" Coultas spent considerable time searching the higher areas of Kusaie for the bird in 1931.
The Kusaie Mountain Starling apparently represents an early invasion of Micronesia, independent of that of any other starling in the area and perhaps the earliest of the three colonizations by starlings in Micronesia. The drawing of the bird as pictured by Kittlitz (1833:pl. 14, fig. 3) shows the long bill to be one of its distinctive characters. This suggests relationship to A. atrifuscus of Samoa, as noted by Mayr (1942a:6). A. atrifuscus is larger than A. opacus with a longer bill and gloss on some of the feathering of the body; it looks a good deal like the drawing of A. corvinus by Kittlitz. A. corvinus may also have some relation to A. magnus of Biak, although this species has a longer tail and a shorter bill. A. corvinus probably has undergone an evolutionary development which parallels that of A. atrifuscus and possibly other species in the Polynesian and Melanesian areas. The ancestral stock from which A. corvinus was derived may have been close to A. grandis, which is found in the Solomon area. A. grandis is a forest bird, somewhat solitary in habits.
Sturnus philippensis (Forster)
Violet-backed Starling
[Motacilla] philippensis Forster, Ind. Zool., 1781, p. 41. (Type locality, Philippines.)
Sturnus philippensis Mayr, Birds Southwest Pacific, 1945, p. 302 (Palau).
Geographic range.—Breeds in Japan. Winters to the Philippine Islands. In Micronesia: Palau Islands—exact locality unknown.
Remarks.—Mayr (1945a:302) records this starling as a migrant visitor to the Palau Islands. Coultas obtained an immature female of this species at Palau on October 13, 1931.