Part 19

Characters.--A large petrel with blackish-brown plumage except for belly and under tail-coverts white and throat, upper breast and flanks pale brown; bill black; legs yellowish; feet black. This oceanic bird differs from other petrels and shearwaters of Micronesia by the presence of a white abdomen in contrast with dark plumage on upper parts, throat, and breast.

Remarks.--A petrel which is referred to this subspecies has been taken once in Micronesia, by Hombron and Jacquinot in the Caroline Islands. It may be pointed out that the subspecies P. r. becki Murphy is known from the sea east of the Bismarck Archipelago and might range into Micronesian waters.

=Pterodroma hypoleuca hypoleuca= Salvin

Stout-billed Gadfly Petrel

Oestrelata hypoleuca Salvin, Ibis, 1888, p. 359. (Type locality, Krusenstern Island = Ailuk, Marshall Islands, fide Fisher, Auk., 63, 1946, pp. 587-588).

Oestrelata hypoleuca Salvin, Cat. Birds British Mus., 25, 1896, p. 409 (Krusenstern); Godman, Monogr. Petrels, pt. 3, 1908, p. 212 (Krusenstern).

Cookilaria hypoleuca hypoleuca Mathews, Syst. Avium Australasianarum, 1, 1927, p. 122, (Marshall Group).

Pterodroma leucoptera hypoleuca Hand-list Japanese Birds, rev., 1932, p. 188 (Marshalls); Hand-list Japanese Birds, 3d ed., 1942, p. 210 (Krusenstern); Fisher, Auk, 63, 1946, pp. 387-388 (Ailuk).

Pterodroma hypoleuca hypoleuca Mayr, Birds Southwest Pacific, 1945, p. 11 (Micronesia).

Geographic range.--Ranges from the Bonins east to the Hawaiians and south to Micronesia. In Micronesia: Marshall Islands--Ailuk.

Characters.--Upper parts grayish except for forehead whitish, crown and nape sooty-black; underparts whitish except for sides of breast sooty-black; legs and feet flesh color except for tips of toes and webs which are black.

Remarks.--In Micronesia, this petrel is known only from the type locality, Krusenstern or Ailuk, Marshall Islands. Fisher (1946: 587-588) has corrected the confusion regarding the exact position of this type locality.

=Phaëthon aethereus mesonauta= Peters

Red-billed Tropic-bird

Phaëthon aethereus mesonauta Peters, Occ. Papers Boston Soc. Nat. Hist., 5, 1930, p. 261. (Type locality, Swan Key, Almirante Bay, Panama.)

Phaeton aethereus Finsch, Ibis, 1880, pp. 329, 333, (Ratak Chain, Marshalls); idem, Journ. f. Ornith., 1880, p. 310 (Kuschai); idem, Ibis, 1881, p. 109 (Kuschai); Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 73 (Kushai, Marshalls); Ogilvie-Grant, Cat. Birds British Mus. 26, 1898, p. 457 (Kushai, Marshalls); Schnee, Zool. Jahrbücher, 20, 1904, p. 390 (Marschall Inseln); Kuroda, in Momiyama, Birds Micronesia, 1922, p. 34 (Kusaie, Marshall Islands).

Phaethon aethereus [?mesonauta] Hand-list Japanese Birds, rev., 1932, p. 187 (Kusaie, Marshalls); Hand-list Japanese Birds, 3d ed., 1942, p. 208 (Kusaie, Marshall Islands).

Geographic range.--Tropical parts of Atlantic and eastern Pacific from Cape Verde Islands west to Panama and Galapagos Islands. In Micronesia: Caroline Islands--Kusaie; Marshall Islands--Ratak Chain.

Characters.--Adult: A large, white sea bird with a long white tail; dorsal surface marked with blackish, transverse vermiculations; bill red; tarsus and foot flesh-colored with a yellowish hue, with plantar surface grayish. Immature: Resembles adults but dark transverse bars are broader; crown blacker; bill yellow.

Remarks.--No specimens have been examined. The Red-billed Tropic-bird is placed in the list of birds known from Micronesia on the basis of two observations by the German ornithologist, Otto Finsch. It has not been reported since his time, and may be considered as an unusual record for the area. I am following the Hand-list of Japanese Birds (Hachisuka et al., 1942:208) in assigning the bird to the subspecies, P. a. mesonauta.

=Phaëthon rubricauda rothschildi= (Mathews)

Red-tailed Tropic Bird

Scaeophaethon rubricauda rothschildi Mathews, Birds Australia, 4, 1915, p. 303. (Type locality, Laysan and Niihau.)

Phaeton rubricaudus Finsch, Journ. f. Ornith., 1880, p. 296 (Carolines); idem, Ibis, 1881, p. 115 (Ponapé).

Phaeton rubricauda Finsch, Proc. Zool. Soc. London, 1880, p. 577 (Ruk); Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 73 (Ruk, Ponapé, Marshalls).

Phaeton rubricauda Ogilvie-Grant, Cat. Birds British Mus., 26, 1898, p. 451 (Caroline Islands); Hartert, Novit. Zool., 7, 1900, p. 11 (Ruk); Hand-list Japanese Birds, rev., 1932, p. 187 (Pagan, Truk, Ponapé, Marshalls).

Scaeophaethon rubricauda Kuroda, in Momiyama, Birds Micronesia, 1922, p. 34 (Mariannes, Ruk, Ponapé, Marshalls).

Phaethon rubricauda rothschildi Yamashina, Tori, 7, 1932, p. 406 (Pagan); idem, Tori, 10, 1940, p. 676 (Maug).