_Sterna Sumatrana_ Raffles, Trans. Linn. Soc. London, 13, pt. 2,
1822, p. 329. (Type locality, Sumatra.)
_Sterna melanauchen_ Kittlitz, Obser. Zool., in Lutké, Voy. "Le
Séniavine," 3, 1836, pp. 306, 308 (Guahan, Ouleai); Hartlaub and
Finsch, Proc. Zool. Soc. London, 1872, pp. 90, 113 (Pelew, Uap);
Gräffe, Journ. Mus. Godeffroy, 2, 1873, p. 123 (Yap); Finsch,
Journ. Mus. Godeffroy, 8, 1875, pp. 5, 41 (Palau); _idem_, Ibis,
1880, pp. 220, 330, 332 (Taluit); _idem_, Journ. f. Ornith., 1880,
p. 295 (Ponapé); _idem_, Proc. Zool. Soc. London, 1880, p. 577
(Ruk); _idem_, Ibis, 1881, pp. 113, 115 (Ponapé); Schmeltz and
Krause, Ethnogr. Abth. Mus. Godeffroy, 1881, pp. 281, 299, 330,
353 (Ponapé, Mortlock, Nukuor, Ruk); Salvadori, Ornith. Papuasia,
3, 1882, p. 444 (Pelew, Mackenzie, Ruk, Ponapé, Marshalls);
Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no. 6,
1890-1891 (1891), p. 74 (Pelew, Uap, Ruk, Luganor, Nukuor, Ponapé,
Taluit); Sanders, Cat. Birds British Mus., 25, 1896, p. 126
(Carolines, Pelews, Marshalls); Nehrkorn, Kat. Eiers., 1899, p.
222 (Palau); Hartert, Novit. Zool., 7, 1900, p. 10 (Ruk); Schnee,
Zool. Jahrbücher, 20, 1904, p. 390 (Marschall-Inseln); Takatsukasa
and Kuroda, Tori, 1, 1915, p. 52 (Ruk, Ponapé); Uchida, Annot.
Zool. Japon., 9, 1918, pp. 483, 488 (Ponapé).
_Sterna sumatrana_ Wetmore, in Townsend and Wetmore, Bull. Mus.
Comp. Zoöl., 63, 1919, p. 186 (Arhno).
_Gygisterna sumatrana_ Kuroda, in Momiyama, Birds Micronesia,
1922, p. 52 (Pelew, Mackenzie, Yap, Ruk, Luganor, Nukuor, Ponapé,
Taluit, Arhno).
_Gygisterna sumatrana sumatrana_ Kuroda, Avifauna Riu Kiu, 1925,
p. 192 (Carolines, Pelews).
_Sterna sumatrana sumatrana_ Yamashina, Tori, 7, 1932, p. 410
(Aruno); Hachisuka, Birds Philippines, 2, 1932, p. 335 (Caroline,
Pelew); Hand-list Japanese Birds, rev., 1932, p. 195 (Palau, Guam,
Saipan, Yap, Truk, Lukunor, Nukuoro, Ponapé, Jaluit, Namu, Arhno,
Majuro, Aurh); Peters, Check-list Birds World, 2, 1934, p. 336
(Caroline Islands); Mayr, List New Guinea Birds, 1941, p. 36
(Micronesia); Hand-list Japanese Birds, 3d ed., 1942, p. 218
(Babelthuap, Koror, Yap, Truk, Lukunor, Nukuoro, Ponapé, Jaluit,
Namu, Arhno, Majuro, Aurh); Mayr, Birds Southwest Pacific, 1945,
p. 24 (Micronesia); Baker, Smithson. Misc. Coll., vol. 107, no.
15, 1948, p. 55 (Peleliu, Ulithi).
_Geographic range._--Micronesia, central Polynesia, northern
Australia, Malaysia, west to India, and north to the Riu Kiu
Islands. In Micronesia: Palau Islands--Babelthuap, Koror, Peleliu;
Caroline Islands--Yap, Ulithi, Truk, Lukunor, Nukuoro, Ponapé;
Marshall Islands--Jaluit, Namu, Majuro, Aurh, Bikini.
_Characters._--Adult: A small tern with a long, forked tail and
white plumage often with pinkish cast except for mantle, back,
rump, tail, wing-coverts, and scapulars which are pale pearl-gray;
band across nape, spot in front of eye, and outer web of outer
primary black; bill and feet black.
Immature: Resembles adult, but black and white mottling on upper
parts.
_Measurements._--Measurements are listed in table 19.
_Specimens examined._--Total number, 15 (8 males, 6 females, 1
female?), as follows: Palau Islands, AMNH--exact locality not
given, 4 (Oct.-Dec.); Caroline Islands, USNM--Ulithi Atoll, 6 (Aug.
15, 16, 20, 22); AMNH--Truk, 1 (Feb. 10); Marshall Islands,
USNM--Bikini, 4 (March 26, April 30).
_Nesting._--Nehrkorn (1899:222) recorded eggs taken at the Palau
Islands. Yamashina (1932a:410) listed the finding of three nests
containing one egg each on September 26, 1931, at Arhno in the
Marshall Islands. The NAMRU2 party obtained no evidence of nesting
at Ulithi or Palau in August and September, 1945. Coultas (field
notes) obtained reports of the finding of two eggs at the Palau
Islands in the period October to December, 1931.
_Parasites._--Uchida (1918:483, 488) records the following
Mallophaga taken at Ponapé from this tern: _Docophorus
albemarlensis_, _Colpocephalum milleri_, and _Colpocephalum
impertunum_.
_Remarks._--There are no records for the Black-naped Tern from the
Mariana Islands, although the species is known from the Palau, Caroline
and Marshall Islands. At Ulithi Atoll, the NAMRU2 party observed these
terns at the islands of Potangeras, Mangejang, Pau, and Losiep in
August, 1945. They were found in groups of 4 to 15, either sitting on
sandy beaches or rocky exposures or flying over the reefs. Unlike the
Crested Tern, these birds appeared quite unafraid of man and would hover
over a freshly killed or wounded individual of their own kind, making of
themselves easy targets. The writer saw only one Black-naped Tern at the
Palau Islands (Peleliu, on September 16, 1945). The birds seem to prefer
the "low" atolls to the "high" volcanic islands of Micronesia.
Two subspecies of _Sterna sumatrana_ are recognized by Peters
(1934:336): _Sterna sumatrana mathewsi_ known from islands of the
western Indian Ocean and _Sterna s. sumatrana_ from islands of Oceania,
Australia, Malaysia, and China coast. There is a considerable area
separating these subspecies. For populations in the Pacific area, other
names which have been proposed are _Sterna sumatrana kempi_ Mathews for
birds from Torres Straits and _Gygis decorata_ Hartlaub for birds from
the Fiji Islands. A study of 201 specimens of this species from various
parts of its range (in the collections of the American Museum of Natural
History and the United States National Museum) shows that there is
little color variation within the species. This observation is the same
as that of Mathews (1912:372).
As listed in table 19, measurements of the length of the wing show
little variation. The length of the tail of birds from localities more
remote from the continent of Asia (Micronesia, Phoenix, Union, Fiji,
Samoa, Tonga, and the islands of the Indian Ocean: Aldabra and
Providence) is, on the average, shorter than the length of the tail of
birds from islands nearer the Asiatic mainland. This shortness is
reflected also in the measurement of the difference between the shortest
and longest tail feather.