_Collocalia bartschi_ Mearns, Proc. U. S. Nat. Mus., 36, 1909, p.
476. (Type locality, Guam.)
_Cypselus inquietus_ Kittlitz (part), Obser. Zool., in Lutké.,
Voy. "Le Séniavine," 3, 1836, p. 304 (Guahan); _idem_ (part),
Denkw. Reise russ. Amer. Micron. und Kamchat., 2, 1858, p. 26
(Guahan).
_Collocalia nidifica_ Gray (part), Ann. Mag. Nat. Hist., (3), 17,
1866, p. 125 (Marianne); _idem_ (part), Hand-list Birds, 1, 1869,
p. 65 (Marianne).
_Collocalia vanicorensis_ Finsch (part), Journ. Mus. Godeffroy,
12, 1876, p. 24 (Marianen); _idem_ (part), Ibis, 1881, p. 105
(Guam); Oustalet, Le Nat., 1889, p. 260 (Mariannes); Wiglesworth
(part), Abhandl. und Ber. Zool. Mus. Dresden, no. 6, 1890-1891
(1891), p. 18 (Marianne); Matschie (part), Journ. f. Ornith.,
1901, p. 112 (Guam, Saipan).
_Collocalia fuciphaga_ Sclater, Proc. Zool. Soc. London, 1865, p.
616 (Marianne); Oustalet (part), Nouv. Arch. Mus. Hist. Nat.
Paris, (3), 7, 1895, p. 187 (Mariannes); Hartert, Novit. Zool., 5,
1898, p. 53 (Rota, Guam, Saipan); Seale, Occ. Papers Bernice P.
Bishop Mus., 1, 1901, p. 46 (Marianas); Safford, Osprey, 1902, p.
60 (Marianas); _idem_, The Plant World, 7, 1904, pp. 84, 263
(Guam); _idem_, Contr. U. S. Nat. Herb., 9, 1905, p. 79 (Guam);
Prowazek, Die deutschen Marianen, 1913, p. 102 (Marianen); Cox,
Island of Guam, 1917, p. 21 (Guam); Bryan, Guam Rec., vol. 13, no.
2, 1936, p. 25 (Guam).
_Collocalia fuchphaga_ Wheeler, Report Island of Guam, 1900, p. 13
(Guam).
_Collocalia fuciphaga fuciphaga_ Oberholser (part), Proc. Acad.
Nat. Sci. Phila., 1906, p. 186 (Guam).
_Collocalia unicolor amelis_ Oberholser, Proc. Acad. Nat. Sci.
Phila., 1906, p. 193 (Guam); Kuroda, in Momiyama, Birds
Micronesia, 1922, p. 63 (Guam).
_Collocalia fuciphaga tachyptera_ Obersolser, Proc. U. S. Nat.
Mus., 42, 1912, p. 20 (Type locality, Guam); Stresemann, Verhandl.
Ornith. Gesellsch. Bayern, 12, 1914, p. 11 (Guam); Takatsukasa and
Kuroda, Tori, 1, 1915, p. 63 (Marianas); Kuroda, in Momiyama,
Birds Michnoseia, 1922, p. 62 (Guam, Saipan, Rota).
_Collocalia unicolor bartschi_ Kuroda, in Momiyama, Birds
Micronesia, 1922, p. 63 (Guam).
_Collocalia fuciphaga bartschi_ Mathews, Syst. Avium
Australasianarum, 1, 1927, p. 402 (Guam); Hand-list Japanese
Birds, rev., 1932, p. 178 (Marianas).
_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)