Charadrius mongolus stegmanni Stresemann
Mongolian Dotterel
Charadrius mongolus stegmanni Stresemann, Ornith. Monatsb., 48, 1940, p. 55. New name for Charadrius mongolus littoralis Stegmann, 1937, preoccupied. (Type locality, Behring Island.)
Charadrius sanguineus Lesson, Man. d'Ornith., 2, 1828, p. 330 (No type locality = Mariana Islands, ex Oustalet, Nouv. Arch. Mus. Hist. Nat. Paris, (3), 8, 1896, p. 48); idem, Traité d'Ornith., 1831, p. 544 (no locality = Mariana Islands); Hartlaub, Journ. f. Ornith., 1854, p. 167 (Mariannen).
Charadrius mongolicus Oustalet, Nouv. Arch. Mus. Hist. Nat. Paris, (3), 8, 1896, p. 48 (Guam, Jaluit, Palaos, Carolines); Hartert, Novit. Zool., 5, 1898, p. 66 (Guam); Seale, Occ. Papers Bernice P. Bishop Mus., 1, 1901, p. 36 (Guam); Safford, Osprey, 1902, p. 68 (Guam).
Aegialitis mongolus Hartert, Novit. Zool., 7, 1900, p. 9 (Ruk).
Aegialis mongola Safford, Contr. U. S. Nat. Herb., 9, 1905, p. 80 (Guam).
Aegialites mongola Cox, Island of Guam, 1917, p. 22 (Guam).
Ochthodromus mongolicus Takatsukasa and Kuroda, Tori, 1, 1915, p. 62 (Marianas, Ruk).
Charadrius mongolus Ridgway, Bull. U. S. Nat. Mus., 50, pt. 8, 1919, p. 132 (Ruk); Mayr, Birds Southwest Pacific, 1945, p. 38 (Micronesia).
Charadrius mongolus mongolus Hartert, Vögel pal. Fauna, 11-12, 1920, p. 1543 (Marianen, Karolinen); Hand-list Japanese Birds, rev., 1932, p. 194 (Guam, Truk, Iuripik, Kusaie, Jaluit, Majuro); Peters, Check-list Birds World, 2, 1934, p. 253 (Carolines, Marianas); Bryan, Guam Rec., vol. 13, no. 2, 1936, p. 24 (Guam); Baker, Smithson. Misc. Coll., vol. 107, no. 15, 1948, p. 50 (Guam, Peleliu, Ulithi).
Cirrepidesmus mongolus mongolus Kuroda, in Momiyama, Birds Micronesia, 1922, p. 44 (Guam, Ruk).
Charadrius mongolus stegmanni Hand-list Japanese Birds, 3d ed., 1942, p. 217 (Guam, Peliliu, Truk, Iuripik, Kusaie, Jaluit, Majuro).
Geographic range.—Breeds in northeastern Siberia and Bering Sea area. Winters south to eastern Malaysia, Melanesia, and Australia. In Micronesia: Mariana Islands—Guam; Palau Islands—Angaur, Peleliu; Caroline Islands—Ulithi, Truk, Iuripik, Kusaie; Marshall Islands—Jaluit, Majuro.
Specimens examined.—Total number, 10 (4 males, 5 females, 1 unsexed), as follows: Mariana Islands, USNM—Guam, 2 (June 7, Sept. 1); AMNH—Guam, 3 (Aug. 15, 18, Nov. 30); Palau Islands, USNM—Peleliu, 3 (Sept. 7-12); Caroline Islands, USNM—Ulithi, 1 (Aug. 22); AMNH—Truk, 1 (Feb. 8).
Remarks.—According to Oustalet (1896:48), Lesson used two specimens of this species, which were collected in the Marianas by the expedition in the "Uranie," as types for his Charadrius sanguineus.
The Mongolian Dotterel is a regular visitor to western Micronesia. It is recorded also from the Marshall Islands, which it probably reaches from the westward by way of the Carolines, since the species has not been recorded in the Hawaiian Islands.
A bird taken by the writer at Guam on June 7, 1945, was in winter plumage and probably nonmigratory. The species was recorded also at Guam in September. At Peleliu in September, 1945, the Mongolian Dotterel was seen frequently on tidal flats by the NAMRU2 party. On September 8 there was a flock of approximately fifty birds, in company with Charadrius leschenaultii, at Akarakoro Point. In August at Ulithi, birds were on the beaches in company with Crocethia alba. At Angaur on September 21, 1945, the species was with other shore birds in small groups at fresh water ponds.
I am tentatively referring all specimens examined to C. m. stegmanni although at this writing (1948) I am inclined to the opinion that a critical reexamination of the referred specimens might reveal one or a few individuals of the subspecies C. m. mongolus Pallas.