Part 58

Specimens examined.--One female from Mariana Islands, USNM--Saipan (Sept. 26).

Remarks.--Marshall (1949:221) took one of two Least Terns at Lake Susupe on Saipan on September 26, 1945. The specimen taken, a female, is in post juvenal molt.

=Thalasseus bergii pelecanoides= (King)

Crested Tern

Sterna pelecanoides King, Surv. Intertrop. and Western Coasts Australia, 2, 1827, p. 422. (Type locality, Torres Strait, northern Queensland.)

Sterna bergii Finsch, Journ. Mus. Godeffroy, 8, 1875, p. 50 (Palau); idem, Proc. Zool. Soc. London, 1877 (1878), p. 781 (Ponapé); idem, Ibis, 1880, pp. 330, 332 (Ratak Chain); 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. 434 (Ruk, Ponapé, Marshalls); Finsch, Mitth. Ornith. Ver. Wien, 1884, p. 51 (Jaluit); Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 74 (Pelew, Luganor, Nukuor, Ruk, Ponapé, Marshall Islands); Hartert, Novit. Zool., 7, 1900, p. 10 (Ruk); Saunders, Cat. Birds British Mus., 25, 1896, p. 89 (Ponapé, Marshalls); Takatsukasa and Kuroda, Tori, 1, 1915, p. 52 (Ponapé); Uchida, Annot. Zool. Japon., 9, 1918, pp. 483, 488 (Ponapé).

Sterna bergeri Schnee, Zool. Jahrbücher, 20, 1904, p. 390 (Marschall-Inseln).

Sterna bergii cristata Stresemann, Novit. Zool., 21, 1914, p. 58 (Truk).

Thalasseus bergii pelecanoides Oberholser, Proc. U. S. Nat. Mus., 49, 1915, p. 523 (Marshall Islands); Kuroda, in Momiyama, Birds Micronesia, 1922, p. 51 (Luganor, Nukuor, Ruk, Ponapé, Marshall Islands); Kuroda, Avifauna Riu Kiu, 1925, p. 188 (Marshall Islands); Hand-list Japanese Birds, rev., 1932, p. 194 (Palau, Faraulep, Truk, Lukunor, Nukuoro, Ponapé, Jaluit, Mille, Aurh, Maloelab, Ailuk); Yamashina, Tori, 10, 1940, p. 677 (Helen Reef, Babelthuap); Hand-list Japanese Birds, 3d ed., 1942, p. 218, (Babelthuap, Helen Reef, Faraulep, Truk, Lukunor, Nukuoro, Ponapé, Jaluit, Mille, Aurh, Maloelab, Ailuk).

Thalasseus bergii cristatus Peters, Check-list Birds World, 2, 1934, p. 342 (Carolines, Marshalls); Mayr, Birds Southwest Pacific, 1945, p. 26 (Micronesia); Baker, Smithson. Misc. Coll., vol. 107, no. 15, 1948, p. 55 (Peleliu, Ngajangel [Kayangel], Truk).

Geographic range.--Malaysia and east coast of Australia south to Tasmania, east to Melanesia and Polynesia, north to Phoenix Islands and Micronesia (see figure 11). In Micronesia: Palau Islands--Helen Reef, Peleliu, Babelthuap; Caroline Islands--Ulithi, Truk, Faraulep, Lukunor, Nukuoro, Ponapé; Marshall Islands--Jaluit, Mille, Aurh, Moloelab, Ailuk, Bikini.

Characters.--Adult: A large, white tern with back, rump, tail, wing-coverts, wing, and axillaries pearl gray; outer edges of primaries pearly grayish-black; crown black with crest; bill greenish-yellow with blackish base; feet black. Crown black, mottled with white and mantle paler in postnuptial plumage.

Immature: Resembles adult, but crown and back dark, mottled with white and crest small.

Measurements.--Measurements of Crested Terns of the Pacific area are listed in table 20.

Specimens examined.--Total number, 10 (6 males, 4 females), as follows: Caroline Islands, USNM--Ulithi, 1 (Aug. 21); AMNH--Truk, 2 (May 7, Dec. 5)--Ponapé, 3 (Nov. 1, 7); Marshall Islands, USNM--Bikini, 4 (March 4, 11, 12).

Parasites.--Uchida (1918:483, 488) obtained the following species of bird lice (Mallophaga) from the Crested Tern at Ponapé: Docophorus albemarlensis and Colpocephalum importunum.

Remarks.--Oberholser (1915:520-526, pl. 66) lists five subspecies (T. b. cristatus, T. b. halodramus, T. b. pelecanoides, T. b. rectirostris, and T. b. poliocercus) in the region including the coast of China, the Riu Kiu Islands, Malaysia, Melanesia, eastern Australia, Polynesia, and Micronesia. Only one subspecies, T. b. cristatus, is recognized in this area by Stresemann (1914:58), Hartert (1921:1695-1696), and Peters (1934:341-342), who mention that there is much variation in size and coloring.

TABLE 20. MEASUREMENTS OF Thalasseus bergii IN THE PACIFIC AREA

Column headings:

A: No. B: Wing C: Longest tail feather D: Shortest tail feather E: Exposed culmen F: Tarsus

=========================+====+=========+=========+=======+=======+====== LOCATION | A | B | C | D | E | F -------------------------+----+---------+---------+-------+-------+------ Thalasseus bergii pelecanoides | | | | Palaus, Carolines, | 6 | 343 | 168 | 82 | 60 | Marshalls | | 334-352 | 153-184 | 80-85 | 58-65 | | | | | | | Christmas, Phoenix, | | | | | | Tuamotus, Society, | 48 | 344 | 170 | 83 | 58 | 27 Fiji, Loyalty, | | 329-362 | 145-198 | 77-92 | 54-64 | 25-29 New Hebrides | | | | | | | | | | | | Eastern Australia | 14 | 345 | 165 | 88 | 58 | 27 | | 338-349 | 152-174 | 84-92 | 55-63 | 26-29 | | | | | | New Guinea, Bismarck, | 18 | 342 | 168 | 81 | 59 | 27 Archipelago, Moluccas| | 332-361 | 144-194 | 75-87 | 53-64 | 26-28 +----+---------+---------+-------+-------+------ Totals | 86 | 344 | 169 | 83 | 58 | 27 | | 329-362 | 144-198 | 75-92 | 53-65 | 25-29 | | | | | | Thalasseus bergii cristatus | | | | | Philippines, China, | 18 | 332 | 162 | 81 | 58 | 28 ormosa, Riu Kius | | 324-342 | 149-182 | 78-87 | 55-64 | 26-30 | | | | | | Thalasseus bergii gwendolenae | | | | Western Australia | 14 | 354 | 171 | 86 | 58 | 27 | | 339-369 | 162-182 | 81-91 | 53-65 | 25-29 -------------------------+----+---------+---------+-------+-------+------

Measurements, as shown in table 20, indicate a wide range of sizes but, in most series, the averages are nearly the same. Nevertheless, it is evident that birds from the coast of China, the Riu Kius, Formosa, and the Philippines have a distinctly shorter wing than birds from the Moluccas, Melanesia, eastern Australia, Polynesia, and Micronesia. Further evidence of this is presented by Kuroda (1925:186) who lists the measurements of the wing of eight Crested Terns from the Riu Kiu Islands as 322 to 340 (average 330). The occurrence of populations with shorter wings has already been pointed out in the work of Oberholser (1915:520-526), who divided the short-winged birds into two subspecies. It seems advisable to recognize but one subspecies, T. b. cristatus, for the birds with short wings and another subspecies, T. b. pelecanoides, to include the birds with the longer wings (see figure 11). The average measurements of the length of wings of these two subspecies, 332, and 344, differ significantly, although there is some overlap in measurements. A few specimens at hand from the western part of Malaysia are in poor condition and not measurable.

Most specimens of T. b. cristatus and T. b. pelecanoides have lighter-colored upper parts than specimens of T. b. velox, but not so light-colored as specimens of T. b. gwendolenae. Size probably is a better character than color to use in separating these groups.

In Micronesia, the NAMRU2 party observed Crested Terns at Ulithi, Peleliu and Truk, in August, September, and December, 1945, respectively. Birds were seen as singles or in small groups flying over the reefs. The birds were wary and difficult to approach, but they were conspicuous and easily identified.

=Procelsterna cerulea saxatilis= W. K. Fisher

Blue-gray Tern

Procelsterna saxatilis W. K. Fisher, Proc. U. S. Nat. Mus., 26, 1903, p. 559. (Type locality, Necker Island, Hawaiian Islands.)

Procelsterna cerulea saxatilis Yamashina, Tori, 10, 1940, p. 678 (Bikar); Hand-list Japanese Birds, 3d ed., 1942, p. 219 (Bikar); Mayr, Birds Southwest Pacific, 1945, p. 27 (Micronesia).