The Avifauna of Micronesia, Its Origin, Evolution, and Distribution

by Rollin H. Baker

Myzomela cardinalis kobayashii Momiyama

Cardinal Honey-eater

Myzomela rubratra kobayashii Momiyama, Birds Micronesia, 1922, p. 19. (Type locality, Pelew Islands.)

Cinnyris rubrater Lesson (part), Dict. Sci. Nat., éd., Levrault, 50, 1827, p. 30 (Pelew); idem (part), Voy. "La Coquille," Zool., 1, 1828, p. 678 (Pelew); idem (part), Man. d'Ornith., 2, 1828, p. 55 (Pelew).

Myzomela rubratra Gray (part), Cat. Birds Trop. Is. Pacific Ocean, 1859, p. 11 (Pelew); Hartlaub (part), Proc. Zool. Soc. London, 1867 (1868), p. 829 (Pelew); Hartlaub and Finsch, Proc. Zool. Soc. London, 1868, pp. 5, 116, 118 (Pelew); Gray (part), Hand-list Birds, 1, 1869, p. 154 (Pelew); Hartlaub and Finsch (part), Proc. Zool. Soc. London, 1872, pp. 89, 94 (Pelew); Finsch (part), Journ. Mus. Godeffroy, 8, 1875, pp. 4, 16 (Palau); idem (part), Journ. Mus. Godeffroy, 12, 1876, pp. 17, 26 (Palau); Forbes (part), Proc. Zool. Soc. London, 1879, p. 270 (Pelew); Finsch (part), Mitth. Ornith. Ver. Wien, 1884, p. 48 (Palau); Gadow, Cat. Birds British Mus., 9, 1884, p. 129 (Pelew); Tristram, Cat. Birds, 1889, p. 206 (Pelew); Wiglesworth (part), Abhandl. und Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 31 (Pelew); Oustalet (part), Nouv. Arch. Mus. Hist. Nat. Paris, (3), 7, 1895, p. 202 (Palaos); Nehrkorn, Kat. Eiers., 1899, p. 79 (Palau-inseln); Seale (part), Occ. Papers Bernice P. Bishop Mus., 1, 1901, p. 57 (Pelew); Reichenow (part), Die Vögel, 2, 1914, p. 482 (Palau); Takatsukasa and Kuroda (part), Tori, 1, 1915, p. 64 (Pelew).

Myzomela rubratra Nehrkorn (part), Journ. f. Ornith., 1879, p. 397 (Palau); Matschie (part), Journ. f. Ornith., 1901, p. 112 (Palau); Takatsukasa and Kuroda (part), Tori, 1, 1915, p. 55 (Pelew); Kuroda, Dobutsu. Zasshi, 28, 1916, p. 71 (Pelew).

Myzomela rubratra kobayshii Kuroda, in Momiyama, Birds Micronesia, 1922, p. 74 (Pelew); Mathews, Syst. Avium Australasianarum, 2, 1930, p. 722 (Pelew).

Myzomela rubratra kurodai Hand-list Japanese Birds (part), rev., 1932, p. 172 (Palau); Hand-list Japanese Birds (part), 3d ed., 1942, p. 190 (Babelthuap, Koror, Peleliu).

Myzomela rubratra kurodai Yamashina, Tori, 10, 1940, p. 674 (Palau).

Myzomela cardinalis kobayashii Mayr, Birds Southwest Pacific, 1945, p. 299 (Palau); Baker, Smithson. Misc. Coll., vol. 107, no. 15, 1948, p. 72 (Peleliu).

Geographic range.—Micronesia: Palau Islands;—Babelthuap, Koror, Garakayo, Peleliu, Angaur.

Characters.—Adult male: Resembles M. c. rubratra, but smaller and with red coloring darker, near "scarlet-red"; margins of wing feathers olivaceous. Differs from adult males of other subspecies of M. cardinalis by red coloring of feathers being darker.

Adult female: Resembles adult female of M. c. dichromata but red coloring darker, top of head only partly red; abdomen, under tail-coverts, and axillaries buff-gray; outer edges of wing and tail feathers light olive. Differs from adult females of other subspecies of M. cardinalis by having top of head only partly red.

Immature male: Resembles adult male, but red coloring lighter and thinly distributed; wings and tail brownish-olive; abdomen and under tail-coverts grayish.

Immature female: Resembles adult female, but red coloring paler and underparts more buffy and less grayish.

Measurements.—Measurements are listed in [table 48].

Specimens examined.—Total number, 42 (28 males, 11 females, 3 unsexed), as follows: Palau Islands, USNM—Koror, 4 (Nov.)—Peleliu, 11 (Aug. 29, 30, 31, Sept. 1, 5); AMNH—exact locality not given, 27 (Oct., Nov., Dec.).

Molt.—Many of the specimens taken from late August to December are in molt. Of the adult males obtained during this period almost a half had enlarged testes.

Food habits.—Stomachs of specimens obtained by the NAMRU2 party in August and September, 1945, contained vegetable matter, seeds and small insects.

Remarks.—Honey-eaters were found by the NAMRU2 party in open woodlands, in coconut groves and about human habitations. They were not seen in dense jungle areas, and appeared to prefer the plantation areas.

The Cardinal Honey-eater at Palau is distinguished from other subspecies of M. cardinalis in Micronesia by its deeper red coloring. In size, it closely resembles the bird at Yap and in the Marianas.

Evolutionary history of Myzomela cardinalis in Micronesia.—The genus Myzomela is found in Australia, northward to Timor, Tenimber, Moluccas, Celebes, Melanesia, Polynesia and Micronesia. The range of the species M. cardinalis includes the islands from the eastern Solomons, New Hebrides, and Loyalty Islands east to central Polynesia and north to Micronesia. It appears likely that M. cardinalis was derived, probably along with M. nigrita, M. lafargei and others, from an ancestral stock in the Melanesian area. Within the species M. cardinalis there is one group of subspecies which exhibits a marked degree of sexual dimorphism, with the males having a much greater amount of red coloration than the females. These subspecies occur in the southern part of the range of the species (Loyalty, Santa Cruz, New Hebrides, and Samoa islands). A second group of subspecies exhibit a lesser amount of sexual dimorphism, the females possessing more of the red coloration and resembling the males more closely. This second group includes subspecies which occur in the more northern part of the range of the species (Solomons, Micronesia, and Rotuma islands). The males of the various subspecies of M. cardinalis vary one from another considerably less than do the females.

Fig. 16. Geographic distribution of Myzomela cardinalis and routes of its dispersal. (1) Probable center of dispersal of Myzomela; (2) ranges of M. c. sanfordi and M. c. pulcherrima in the Solomon Islands; (3) M. c. rubratra; (4) M. c. dichromata; (5) M. c. major; (6) M. c. kurodai; (7) M. c. kobayashii; (8) M. c. saffordi; (9) M. c. chermesina; (10) range of M. cardinalis in the Santa Cruz, New Hebrides, Banks and Loyalty islands; (11) M. c. nigriventris.

[Figure 16] shows the probable routes of colonization used by M. cardinalis to attain its present distribution in the Pacific islands. The subspecies in the eastern Solomon Islands (M. c. pulcherrima Ramsey and M. c. sanfordi Mayr) may be representative of the first colonization by the supposed ancestral stock. From a focal point in this area, M. cardinalis has dispersed by what may be considered as two routes. One route evidently was to the south as far as the Loyalty Islands with a side branch extending to the Samoan Islands where M. c. nigriventris Peale occurs. The second route extended north to the islands of Micronesia. The Caroline Islands were seemingly inhabited initially, with invasions of the Palaus made via Yap, and of the Marianas via Kusaie or Ponapé (as indicated by the comparison of specimens). Mayr (in conversation) has pointed out the close relationship between the subspecies in Micronesia and M. c. chermesina Gray of Rotuma Island. This subspecies at Rotuma, which is located between Santa Cruz and Samoa, resembles closely M. c. dichromata of Ponapé, especially in the case of the female. It is evident that the honey-eater arrived at Rotuma from Micronesia, rather than from the Solomon and Santa Cruz area to the west.