Aplonis pelzelni Finsch
Ponapé Mountain Starling
Aplonis pelzelni Finsch, Proc. Zool. Soc. London, 1875 (1876), p. 644. (Type locality, Ponapé.)
Aplonis pelzelni Finsch, Journ. Mus. Godeffroy, 12, 1876, pp. 17, 32, pl. 2, fig. 3 (Ponapé); idem, Proc. Zool. Soc. London, 1877 (1878), p. 779 (Ponapé); idem, Journ, f. Ornith., 1880, p. 290 (Ponapé); idem, Ibis, 1881, pp. 110, 112, 115 (Ponapé); Schmeltz and Krause, Ethnogr. Abth. Mus. Godeffroy, 1881, p. 281 (Ponapé); Sharpe, Cat. Birds British Mus., 13, 1890, p. 136 (Ponapé); Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 43 (Ponapé); Oustalet, Nouv. Arch. Mus. Hist. Nat. Paris, (3), 7, 1895, p. 215 (Ponapé); Bolau, Mitteil. Naturhist. Mus. Hamburg, 1898, p. 62 (Ponapé); Matschie, Journ. f. Ornith., 1901, pp. 111, 112 (Ponapé); Dubois, Syn. Avium, 1, 1902, p. 542 (Ponapé); Reichenow, Die Vögel, 2, 1914, p. 355 (Ponapé); Takatsukasa and Kuroda, Tori, 1, 1915, p. 64 (Ponapé); Kuroda, in Momiyama, Birds Micronesia, 1922, p. 70 (Ponapé); Mathews, Syst. Avium Australasianarum, 2, 1930, p. 849 (Ponapé); Hand-list Japanese Birds, rev., 1932, p. 170 (Ponapé); Bequaert, Mushi, 12, 1939, p. 82 (Ponapé); Mayr, Proc. 6th Pacific Sci. Congr., 4, 1941, pp. 204, 213 (Ponapé); Bequaert, Occ. Papers Bernice P. Bishop Mus., 16, 1941, p. 290 (Ponapé); Mayr. Birds Southwest Pacific, 1945, p. 298 (Ponapé).
Aplornis pelzelni Hand-List Japanese Birds, 3d ed., 1942, p. 189 (Ponapé).
Geographic range.—Micronesia: Caroline Islands—Ponapé.
Characters.—Adult: A small, dark starling with upper parts sooty-brown, darker on head with forehead and lores blackish; wings, rump, upper tail-coverts, and tail lighter and more brownish than head; underparts paler and washed with olive-brown; bill and feet black; iris brown.
Immature: Resembles adult, but lighter brown, especially the underparts.
A. pelzelni differs from A. opacus by having no gloss on the feathers, smaller size, more slender bill, and a brown iris.
Measurements.—Measurements are listed in [table 46].
Specimens examined.—Total number, 59 (32 males, 24 females, 3 unsexed), from Caroline Islands, AMNH—Ponapé (Dec).
Nesting.—Coultas (field notes) obtained reports that the Ponapé Mountain Starling nests in cavities in trees and lays two eggs.
Table 46. Measurements of Aplonis pelzelni
Table 46. Measurements of Aplonis pelzelni
| Number and Sex | Wing | Tail | Exposed Culmen | Depth of bill at nostril | Tarsus |
10 adult males | 103 | 65 | 20.0 | 6.5 | 27 |
| 101-105 | 63-67 | 19.0-21.0 | 6.0-7.0 | 26-28 | |
10 adult females | 99 | 61 | 19.5 | 6.0 | 27 |
| 97-102 | 57-64 | 19.5-20.5 | 6.0-6.5 | 26-27 |
Parasites.—Bequaert (1939:82 and 1941:290) records the fly (Hippoboscidae), Ornithoica pusilla, from A. pelzelni.
Remarks.—Coultas (field notes) writes that "the Mountain Starling is a bird of the true mountain forest.... I did not record it below 1,400 feet. Natives tell me that the Mountain Starling formerly covered the whole of the island and that now some individuals can be found on the low atoll of Ant, to the westward of Ponapé. Unfortunately, I was not permitted to visit either Ant or Pakin." Coultas notes also that the birds are quiet and usually travel in pairs. They are easily attracted by squeaking the lips against the hand or by the cries of a wounded bird. Many of these starlings were taken in fruit trees. Coultas describes the call of A. pelzelni as "weaker and finer" than that of A. opacus. These two species may be found together, according to Coultas, but A. opacus is apparently the more aggressive and often drives A. pelzelni away. Richards (in litt.) found this bird to be "very rare" while on his visit to Ponapé in 1947-1948. He observed two individuals on January 15, 1948, at an elevation of approximately 600 or 700 feet. A male was taken.
Evolutionary history of Aplonis pelzelni.—The Ponapé Mountain Starling is a distinctive bird which evidently represents an ancient and single colonization of Micronesia. It lacks the green gloss which is found on many of the other starlings of the Pacific region. It has a brown iris, and the immatures lack the streaked underparts which are characteristic of A. opacus and other species. The structure of its wing resembles that of A. opacus, but the primaries are more rounded. It is apparently better adapted to forested uplands, whereas A. opacus and its relatives, A. cantoroides and A. feadensis, appear to prefer lowland forests and coconut plantations. In habits and habitat preference, A. pelzelni seems to resemble A. santovestris, which is restricted to mountain environment on Espiritu Santo in the New Hebrides. The describers of this starling, Harrisson and Marshall (1937:149), write that "Aplonis santovestris apparently most closely resembles A. pelzelni from Ponapé, especially in bill and tarsus." According to the description, A. santovestris is approximately the size of A. pelzelni with brownish coloring, crown dark brown, lower back and rump dark rufous, wing and tail blackish-brown, underparts rufous-brown, and iris grayish-green. These two birds are separated geographically and apparently exhibit evidences of parallel development. Possibly they came from a common ancestral stock. Mayr (1941b:204) writes that A. pelzelni belongs with the starlings of the Polynesian area. I have compared A. pelzelni with other starlings of the Southwest Pacific, including A. feadensis, A. cantoroides, and A. zealandicus, but see no close resemblances.