Part 79

Collocalia vanikorensis bartschi Mayr, Amer. Mus. Novit., no. 828, 1936, p. 11 (Marianne); Hand-list Japanese Birds, 3d ed., 1942, p. 198 (Saipan, Rota, Guam).

Collocalia germani bartschi Mayr, Amer. Mus. Novit., no. 915, 1937, p. 18 (Marianne).

Collocalia inexpectata bartschi Peters, Check-list Birds World, 4, 1940, p. 224 (Marianne); Mayr, Birds Southwest Pacific, 1945, p. 292 (Marianas); Watson, The Raven, 17, 1946, p. 41 (Guam); Downs, Trans. Kansas Acad. Sci., 49, 1946, p. 105 (Tinian); Stott, Auk, 64, 1947, p. 526 (Saipan); Baker, Smithson. Misc. Coll., vol. 107, no. 15, 1948, p. 63 (Guam, Rota).

Collocalia inexpectata Strophlet, Auk, 63, 1946, p. 538 (Guam); Baker, Condor, 49, 1947, p. 125 (Guam).

Geographic range.--Micronesia: Mariana Islands--Guam, Rota, Tinian, Saipan.

Characters.--Resembles C. i. pelewensis, but with wing shorter; upper parts lighter; underparts more brownish and lacking dark shaft-streaks on breast and abdomen; feathers on lores whiter basally.

Measurements.--Measurements are presented in table 30.

Weights.--The present author (1948:63) lists the weights of seven adult males as 6.4-7.3 (6.8); of three adult females as 6.8-7.6 (7.1). These birds were taken at Guam.

Specimens examined.--Total number, 48 (17 males, 19 females, 12 unsexed), as follows: Mariana Islands, USNM--Guam, 21 (Jan. 29, May 20, June 21, July 20, 29)--Rota, 1 (Oct. 27); AMNH--Guam, 18 (Jan. 22, 29, Feb. 15, July 10, Aug. 11, 12)--Saipan, 8 (Sept. 17).

Remarks.--The taxonomic relationships of the species and subspecies of the genus Collocalia are not fully known. The many different name combinations applied to the five kinds named from Micronesia are evidence of the lack of agreement among previous writers as to the correct systematic positions of the kinds. The genus is widely distributed in southeastern Asia and adjacent islands and is divisible into a number of species and subspecies. This diversity is apparently influenced by the restriction of the birds to local habitats caused, as Stresemann (1931b:83) states, by the necessity of staying by their nesting areas which are in caves. Stresemann also points out that the birds are thus dependent on "narrowly limited ecological conditions." The birds are confined to certain areas and are, therefore, isolated from other populations. Most of the volcanic islands of Micronesia have numerous caves which are suitable to the swiftlets for nesting. C. inexpectata evolved in the Malayan region and apparently spread to Micronesia via the Philippines to Palau and to the Marianas. The two subspecies of C. inexpectata in Micronesia resemble closely those to the westward but are smaller. I am following Peters (1940:224) in the treatment of these, and although some future reviser may rearrange these species and subspecies, it appears to me that the Micronesian swiftlets fall into the two natural groups (C. inexpectata and C. inquieta) now recognized, even though their parent stocks in Malaysia, in my opinion, are inadequately known.

At Guam and Rota, the NAMRU2 party found swiftlets concentrated at cliff areas, flying about in large groups. Away from the cliffs fewer were seen and singles were observed in woodland openings, over fields, and in the coconut groves. On May 18, 1945, a colony of nesting birds was found approximately two miles east of Agaña on Guam. This colony was in a coral sink-hole which was approximately 75 feet deep and 60 feet in diameter. The nests were grouped in clusters of 5 to 25 or more, on underhanging ledges, sheltered from the light. The nests, which were fastened securely to the irregular ledges, were knocked down by shots from our collecting guns. Approximately 250 nests were found; no eggs were observed, the nests containing young birds. The young were in various stages of development; some were with little feather growth, others were completely feathered. Nests examined contained only one young each. The pile of guano below each cluster of nests was large; an estimate made at the time indicated that there were 10 or more tons in each pile. Guano deposits in large quantities were found also in caves at Amantes Point, Guam.

=Collocalia inquieta inquieta= (Kittlitz)

Carolines Swiftlet

Cypselus inquietus Kittlitz, Obser. Zool., in Lutké, Voy. "Le Séniavine," 3, 1836, p. 285. (Type locality, Ualan.)

Cypselus inquietus Kittlitz (part), Denkw. Reise russ. Amer. Micron. und Kamchat., 2, 1858, p. 26 (Ualan).

Collocalia ualensis Streubel, Isis, 1848, p. 368 (no type locality = Kusaie?).

Collocalia nidifica ualensis Gray, Ann. Nat. Hist., 17, 1866, p. 123 (Caroline Islands = Kusaie?).

Collocalia vanicorensis Finsch (part), Journ. Mus. Godeffroy, 12, 1876, p. 24 (Ualan); idem (part), Proc. Zool. Soc. London, 1880, p. 575 (Kuschai); idem (part), Journ. f. Ornith., 1880, pp. 285, 298 (Kuschai); idem (part), Ibis, 1881, pp. 104, 108 (Kushai); Wiglesworth (part), Abhandl. und Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 18 (Ualan); Matschie (part), Journ. f. Ornith., 1901, p. 112 (Ualan).

Collocalia fuciphaga Hartert (part), Cat. Birds British Mus., 16, 1892, p. 498 (Kuschai); Oustalet (part), Nouv. Arch. Mus. Hist. Nat. Paris, (3), 7, 1895, p. 190 (Oualan).

Collocalia fuciphaga fuciphaga Oberholser (part), Proc. Acad. Nat. Sci. Phila., 1906, p. 186 (Ualan).

Collocalia fuciphaga vanikorensis Oberholser (part), Proc. U. S. Nat. Mus., 42, 1912, p. 20 (Kusaie).

Collocalia fuciphaga inquieta Stresemann, Verhandl. Ornith. Gesellsch. Bayern, 12, 1914, pp. 9, 11 (Ualan); Kuroda (part), in Momiyama, Birds Micronesia, 1922, p. 62 (Kusaie); Hand-list Japanese Birds (part), rev., 1932, p. 179 (Kusaie).

Collocalia inquieta inquieta Mayr, Amer. Mus., Novit., no. 915, 1937, p. 11 (Kusaie); Peters, Check-list Birds World, 4, 1940, p. 225 (Kusaie); Mayr, Birds Southwest Pacific, 1945, p. 292 (Kusaie).

Collocalia vanikorensis inquieta Hand-list Japanese Birds, 3d ed., 1942, p. 199 (Kusaie).

Geographic range.--Micronesia: Caroline Islands--Kusaie.

Characters.--Adult: Upper parts dark (sooty-black) with a slight greenish gloss on head and back and a more conspicuous bluish-purple gloss on the wings and tail; feathers of lores white, tipped with black; underparts smoky-gray; feet brownish; bill black; iris dark brown.

Measurements.--Measurements are presented in table 31.

Specimens examined.--Total number, 42 (21 males, 20 females, 1 unsexed), as follows: Caroline Islands, USNM--Kusaie, 1 (Feb. 8); AMNH--Kusaie, 41 (Jan., Feb., March).