Systematics of Megachiropteran Bats in the Solomon Islands Part 4

woodfordi_ can be included in the _Pteropus scapulatus_ group of Andersen (1912:402).

=Pteropus hypomela.n.u.s=

_Pteropus hypomela.n.u.s_ is a wide-ranging species of flying fox having at least seven subspecies; three occur in southeastern Asia, two on and near Celebes, and two in New Guinea and islands adjacent to the southeastern coast of New Guinea, including one island in the Solomons (Ellerman and Morrison-Scott, 1966:95; Laurie and Hill, 1954:32-33).

[Ill.u.s.tration: FIG. 5. Distribution of _Pteropus hypomela.n.u.s luteus_ ([TW]), _Pteropus admiralitatum solomonis_ ([RW]), _Pteropus a.

colonus_ ([BW]), _Pteropus a. goweri_ ([LW]), _Pteropus tonga.n.u.s geddiei_ ([RTW]), and _Pteropus howensis_ ([BC]). For names of islands see Fig. 2.]

=Pteropus hypomela.n.u.s luteus= Andersen

1908. Pteropus hypomela.n.u.s luteus Andersen, Ann. Mag. Nat. Hist., ser. 8, 2:362, October, type from Kiriwini Island, Trobriand Islands; 1912, Andersen, Catalogue of the Chiroptera ... British Museum, 1:128; 1947, Sanborn and Beecher, Jour. Mamm., 28:388, November 19, from Banika Island, Russell Islands.

_Specimens examined._--None.

_Remarks._--Andersen (1908:362) identified specimens of _Pteropus hypomela.n.u.s_ from eastern New Guinea and three nearby islands (Conflict Islands, Trobriand Islands, and Woodlark Island) as _P. hypomela.n.u.s luteus_. Sanborn and Beecher (1947:388) identified a female from Banika Island in the Solomons as of this subspecies although this specimen was darker and had a slightly smaller skull than typical _P. hypomela.n.u.s luteus_. They noted that the pelage of the venter of the female was uniformly dark rather than the typical Ochraceous-Buff to Cream-Buff; the specimen was regarded as a dark phase of the subspecies. Although not recorded previously for _luteus_, other subspecies of _P.

hypomela.n.u.s_ were known in dark phase as well as pale and intermediate phases of coloration (Andersen, 1912:122). The reported occurrence of _P. h. luteus_ on Banika Island extended the known geographic range about 450 miles eastward from Woodlark Island.

=Pteropus admiralitatum=

Three subspecies, all about the same size but differing in coloration, have been described from the Solomon Islands. _P. a. goweri_ is known only from Gower (Ndai) Island, notably removed from the western chain of islands inhabited by _P. a. colonus_ and _P. a. solomonis_. Only one other subspecies, from the Admiralty Islands, is known.

=Pteropus admiralitatum solomonis= Thomas

1904. _Pteropus solomonis_ Thomas, Novit. Zool., 11:597, type from Ghizo Island; 1912, Andersen, Catalogue of the Chiroptera ...

British Museum, 1:149; 1931, Sanborn, Publ. Field Mus. Nat. Hist., Zool. Ser., 18:12, February 12, from Ronongo (Ganongga), Vella Lavella, and Narovo (Simbo) islands; 1947, Sanborn and Beecher, Jour. Mamm., 28:389, November 19, from Banika and Guadalca.n.a.l islands.

1954. _Pteropus admiralitatum solomonis_, Laurie and Hill, List of land mammals of New Guinea, Celebes and adjacent islands, p. 33, June 30.

_Specimens examined._--None.

_Remarks._--Andersen (1912:149) considered _Pteropus admiralitatum_, and especially the subspecies _P. a. solomonis_, to be the easternmost "representative" of _Pteropus hypomela.n.u.s_. In comparison with _P.

hypomela.n.u.s luteus_, _P. a. solomonis_ differs mostly in size, being much smaller (length of forearm about 110 rather than 134). It is now known that both species occur on Banika Island in the Solomons.

The subspecies _P. a. solomonis_ has been recorded from a "chain" of islands that included Vella Lavella, Simbo, Ghizo, Ganongga, Banika, and Guadalca.n.a.l (see Fig. 5).

=Pteropus admiralitatum colonus= Andersen

1908. _Pteropus colonus_ Andersen, Ann. Mag. Nat. Hist., ser. 8, 2:363, October, type from Shortland Island; 1912, Andersen, Catalogue of the Chiroptera ... British Museum, 1:150; 1931, Sanborn, Publ. Field Mus. Nat. Hist., Zool. Ser., 18:12, February 12, from Mono Island.

1954. _Pteropus admiralitatum colonus_, Laurie and Hill, List of land mammals of New Guinea, Celebes and adjacent islands, p. 33, June 30.

1887. _Pteropus hypomela.n.u.s_ (part), Thomas, Proc. Zool. Soc.

London, p. 471, December 4; 1898, Trouessart, Catalogus Mammalium ..., 1:82, from "I. Salomonis."

1899. _Pteropus (Spectrum) hypomela.n.u.s_ (part), Matschie, Die Megachiroptera ... naturkunde, p. 24.

_Specimens examined._--None.

_Remarks._--_Pteropus admiralitatum colonus_ is the largest of the three subspecies that occur in the Solomon Islands. It closely resembles _P.

hypomela.n.u.s luteus_, except in being smaller throughout (see Andersen, 1912:151-152, for measurements) and darker on the underparts.

This bat has been found in a group of small islands (Alu, Mono, and Shortland) about 30 miles south of Bougainville. Because of this proximity and because yet another subspecies of this species occurs northward of Bougainville, it is interesting that neither Troughton (1936) nor Pohle (1953) included the species in their faunal lists for Bougainville.

Andersen (1912:152) indicated that the M1 in _P. admiralitatum colonus_ is smaller than in _P. a. solomonis_, the subspecies found in islands to the southeast (4.4-4.5 and 5.2, respectively), but Sanborn (1931:13) studied specimens of these two subspecies that overlapped in size of M1.

=Pteropus admiralitatum goweri= Tate

1934. _Pteropus goweri_ Tate, Amer. Mus. Novit., 718:1, May 4, type from Gower (Ndai) Island.

1954. _Pteropus admiralitatum goweri_, Laurie and Hill, List of land mammals of New Guinea, Celebes and adjacent islands, p. 33, June 30.

_Specimens examined._--None.

_Remarks._--_Pteropus admiralitatum goweri_ was described from six specimens collected in 1930 by the Whitney South Sea Expedition (Tate, 1934:1). This subspecies closely resembles the other two subspecies of _P. admiralitatum_ (_colonus_ and _solomonis_) found in the Solomon Islands. Color and length of forearm (see key on p. 793) seem to be the only reliable criteria for distinguishing between these subspecies. The longitude of Gower Island, 160 34' E, was incorrectly listed in Laurie and Hill (1954:152) as 159 34' E.

=Pteropus howensis= Troughton

1931. _Pteropus howensis_ Troughton, Proc. Linn. Soc. New South Wales, 56:204, June 24, type from Lord Howe Islands (Ontong Java); 1950, Sanborn and Nicholson, Fieldiana:Zool., 31:329, August 31.

_Specimens examined_ (one male, three females, and two s.e.x unknown; two embryos in alcohol).--Liuniuwu, Lord Howe Islands (Ontong Java) in August, USNM 278703-6, USNM 279715-6.

_Measurements._--Average and extreme measurements of one male and three females are as follows: Length of head and body, 185.2 (176-196); hind foot, 34.5 (33-36); ear, 21.5 (21-23); forearm not measured [broken in all specimens examined]. Cranial measurements of a male and a female are, respectively, as follows: Greatest length of skull, 55.3, 53.8; condylobasal length, 54.2, 52.8; palatal length, 26.7, 26.0; zygomatic breadth, 30.6, 29.9; breadth of braincase, 19.9, 19.2; breadth across first upper molars, 14.3, 14.3; length of maxillary tooth-row, 20.7, 19.6; length of mandibular tooth-row, 23.1, --.

_Remarks._--Apparently _Pteropus howensis_ is confined to Ontong Java (Lord Howe Islands) located northeastward of the main body of islands that const.i.tute the Solomon Archipelago (see Fig. 5). According to A. J.

Nicholson, who collected the specimens listed above, _P. howensis_ is not abundant in Ontong Java. He related this circ.u.mstance to the fact that these small islands are nothing more than parts of a coral atoll used almost entirely for the production of coconuts (see Sanborn and Nicholson, 1950:329).

Specimens of _Pteropus howensis_ deposited in the U. S. National Museum agree well in most ways with the original description of the species by Troughton (1931:204-205). Slight variation in color is evident; in two specimens, the mantle, just posterior to the ears, is Ochraceous-Buff.

The relationship of this species to other kinds of _Pteropus_ known from Melanesia is not clear. Troughton (1931:204, 206) compared _P. howensis_ with _P. hypomela.n.u.s_ and _P. admiralitatum_ and found that it resembled each of them. Tate (1934:2) noted that the skull of _P. admiralitatum goweri_ was similar to that of _P. howensis_ in structure. The latter species is, however, larger (length of forearm 122 according to Troughton, 1931:205) than any subspecies of _P. admiralitatum_ (length of forearm 108-112). Also, the cheek-teeth of _P. howensis_ that I have studied are relatively larger than those of either _P. hypomela.n.u.s_ or _P. admiralitatum_. Furthermore, in _P. howensis_ there is a small but distinct cusp located medio-posteriorly on P4 (most noticeable in young individuals) that is more reduced or undeveloped in specimens of the other two species. Cheek-teeth of _P. howensis_ resemble those in a dull-colored specimen of _P. tonga.n.u.s_ from Fiji Island with which I compared the specimens listed above.

Weights and crown-rump lengths of the two embryos (in an advanced stage of development) examined were 20 and 29 grams and 43 and 51 mm.

(apparently these are the specimens listed by Sanborn and Nicholson, 1950:329).

=Pteropus tonga.n.u.s=

_Pteropus tonga.n.u.s_ has at least three subspecies, one of which has been recorded from the Solomons. The species ranges from a small island off the eastern coast of New Guinea, where there is an endemic subspecies, eastward to Tonga and the New Hebrides (Laurie and Hill, 1954:33-34).

Felten (1964_a_) recently has reported on the species in the New Hebrides.

=Pteropus tonga.n.u.s geddiei= MacGillivary