Systematics of Megachiropteran Bats in the Solomon Islands Part 6

The color of _P. r. lavella.n.u.s_ is close to that of _P. r. rubia.n.u.s_ except that the crown, mantle, and foreneck are near Chestnut-Brown, the basal portions of hair black, and the fur of the venter, from sternum to pectoral region, is dark, almost black (compare with description of _P.

r. rubia.n.u.s_ under account of that subspecies).

Measurements of the male examined are greater than those of the female studied. Andersen (1912:259) noted that the canine teeth are heavier in males than in females.

=Pteropus rayneri monoensis= Lawrence

1945. _Pteropus rayneri monoensis_ Lawrence, Proc. New England Zool. Club, 23:63, March 26, type from Mono (Treasury); 1954, Laurie and Hill, List of land mammals of New Guinea, Celebes and adjacent islands, p. 36, June 30.

_Specimens examined._--None.

_Remarks._--_Pteropus rayneri monoensis_ is the most recently described subspecies of _P. rayneri_. Lawrence (1945:63) judged that in most ways this bat is intermediate between _P. r. grandis_ and _P. r. lavella.n.u.s_.

Coloration of _monoensis_ indicates affinity with the former, whereas length of forearm (145-148) approaches that in the latter. The small skull, narrow palate, and whitish rump patch of _monoensis_ are differences that distinguish it from _grandis_ and _lavella.n.u.s_. The relatively isolated position of Mono Island may have been important in establishment of the distinctive features of this bat.

Lawrence (1945:65) quoted a collector as stating: "They [individuals of _P. r. monoensis_] rest quietly during the day in the tops of heavy-leaved, tall jungle trees, and start flying about dusk, looking for feeding spots. There is usually quite a flight for fifteen to twenty minutes at twilight...."

No additional specimens of this subspecies have been collected on small adjacent islands and _monoensis_ may therefore be confined to Mono Island.

=Pteropus rayneri cognatus= Andersen

1908. _Pteropus cognatus_ Andersen, Ann. Mag. Nat. Hist., ser. 8, 2:365, October 1, type from San Cristobal; 1912, Andersen, Catalogue of the Chiroptera ... British Museum, 1:251; 1931, Sanborn, Publ. Field Mus. Nat. Hist., Zool. Ser., 18:15, February 12, from San Cristobal and Ugi; 1954, Laurie and Hill, List of land mammals of New Guinea, Celebes and adjacent islands, p. 35, June 30.

1962. _Pteropus rayneri cognatus_, Hill, The natural history of Rennell Island, British Solomon Islands, 4:9, February.

1870. _Pteropus rayneri_ (part), Gray, Catalogue of monkeys, lemurs and fruit-eating bats ... British Museum, p. 108, from San Cristobal; 1878, Dobson, Catalogue of the Chiroptera ... British Museum, p. 33.

1904. _Pteropus_ (_Spectrum_) _rayneri_ (part), Trouessart, Catalogus Mammalium ..., Suppl., p. 51.

_Specimens examined._--None.

_Remarks._--Specimens of _Pteropus rayneri cognatus_ first were reported under the name _Pteropus rayneri_ based on three specimens (one from San Cristobal and two from Guadalca.n.a.l). Because the description was based mostly on the two specimens from Guadalca.n.a.l, the name _rayneri_ is applicable to the bats from that island. Andersen (1908:365) thought that specimens that he studied, from San Cristobal, were specifically distinct from _P. rayneri_ and he proposed the name _Pteropus cognatus_ for them. Later, Hill (1962:9) reduced _cognatus_ to subspecific status under _P. rayneri_.

Presently _P. r. cognatus_ is known only from San Cristobal and the small adjacent island of Ugi (see Fig. 6).

=Pteropus rayneri rennelli= Troughton

1929. _Pteropus rennelli_ Troughton, Rec. Australian Mus., 17:193, September 4, type from Rennell Island; 1954, Laurie and Hill, List of land mammals of New Guinea, Celebes and adjacent islands, p. 35, June 30.

1962. _Pteropus rayneri rennelli_, Hill, The natural history of Rennell Island, British Solomon Islands, 4:7, February.

_Specimens examined._--None.

_Remarks._--Until recently, _Pteropus rayneri rennelli_ was known from but a single specimen. Hill (1962:7) reported two additional specimens and pointed out that _P. r. cognatus_ and _P. r. rennelli_ probably represent the extremes of an east-west cline in size. _P. r. rennelli_ and _P. r. cognatus_ differ from other subspecies of the species in lacking tricolored pelage on the dorsum, but their short rostrum clearly indicates affinity with other members of this complex group in the Solomon Islands (Hill, 1962:8).

The relations.h.i.+p of the subspecies _rennelli_ and _cognatus_ is close, both geographically and genetically. Longer forearm, longer metacarpals, and longer mandibular tooth-row serve to differentiate _rennelli_ from _cognatus_.

=Pteropus woodfordi= Thomas

1888. _Pteropus woodfordi_ Thomas, Ann. Mag. Nat. Hist., ser. 6, 1:156, February, type from Guadalca.n.a.l; 1888, Thomas, Proc. Zool.

Soc. London, p. 472, December 4; 1898, Trouessart, Catalogus Mammalium ..., 1:78; 1907, Elliot, Field Columbian Mus., Zool.

Ser., 8:491; 1912, Andersen, Catalogue of the Chiroptera ...

British Museum, 1:410, from New Georgia and Guadalca.n.a.l; 1931, Sanborn, Publ. Field Mus. Nat. Hist., Zool. Ser., 18:19, February 12, from Kolombangara; 1947, Sanborn and Beecher, Jour. Mamm., 28:389, November 19, from Banika and Guadalca.n.a.l; 1954, Laurie and Hill, List of land mammals of New Guinea, Celebes and adjacent islands, p. 39, June 30.

1899. _Pteropus (Sericonycteris) woodfordi_, Matschie, Die Megachiroptera ... naturkunde, p. 83; 1904, Trouessart, Catalogus Mammalium ..., Suppl., p. 54.

1945. _Pteropus austini_ Lawrence, Proc. New England Zool. Club, 23:59, March 26, from Florida.

_Specimens examined_ (four males and three females; five in alcohol and two skin-onlys).--Fauro, in April, 23727, 23790; Guadalca.n.a.l in May and June, 23823, 23931; Pavuvo (Russell Islands) in August and October, USNM 277887, USNM 283872-3.

_Measurements._--External measurements of two males and two females are, respectively, as follows: Length of head and body, 152, 128, 132, 155; hind foot, 29, 26, 31, 28; ear, 16, 14, 14, 17; length of forearm, 79, 76, 86, 90.

_Remarks._--Heretofore, _Pteropus woodfordi_ was known from New Georgia, Guadalca.n.a.l, Kolombangara, and Banika (see Fig. 7); specimens from Fauro and Pavuvo islands, listed above, provide new northern localities of record for this species.

Judging by small size and unfused epiphyses, a bat obtained in April and another obtained in June are subadults. Specimens of adults, examined by me, agree well with the descriptions of _P. woodfordi_ by Thomas (1888_a_:156) and Andersen (1912:407-409), but are slightly smaller than specimens listed by Sanborn and Beecher (1947:389). Color of pelage in this species seems to vary. Adults seen have a pale head and mantle, contrasting strongly with the dark back. Andersen (1912:409) and Lawrence (1945:61) discussed individuals that had scattered silvery hairs mixed with dark fur dorsally and darker mantles that did not contrast noticeably with the rest of the dorsum.

Lawrence (1945:389) named _Pteropus austini_ as a new species closely related to _P. woodfordi_ and other species of the _P. scapulatus_ group of Andersen (1912:402) and Tate (1942:336). Sanborn and Beecher (1947:389), studied a series of _P. woodfordi_ from Banika and Guadalca.n.a.l and found that skulls of two subadults agreed well with cranial characteristics ascribed to _P. austini_, which was based on two subadults. Lawrence (1945:61) stated also that "the interfemoral membrane is entirely absent medially in _austini_, while in _woodfordi_ it is present as a barely discernible ridge 8 mm. wide." Andersen (1912:408) had earlier reported that in the type of _woodfordi_ the interfemoral membrane was "undeveloped in [the] centre." In 13 adults (in alcohol) studied by Sanborn and Beecher (1947:389), as well as in adults examined by me, the uropatagium is not present. In size, however, these specimens agree with dimensions given for _woodfordi_ by Thomas (1888_a_:156) and Andersen (1912:410); for example, length of forearm is 93-99. According to Lawrence (1945:59) _austini_, in which the interfemoral membrane is lacking, is smaller than _woodfordi_ and has a forearm of about 84. In two juveniles of _P. woodfordi_ in the U. S.

National Museum, the medially-developed interfemoral membrane is about 7 wide. One specimen has small but distinct calcars whereas the other (slightly larger) apparently lacks calcars. This suggests individual variation in the presence or absence, as well as in the size, of the uropatagium in _Pteropus woodfordi_.

Sanborn and Beecher (1947:389) decided that "until fully adult specimens showing the characters of _austini_ are available, it best be considered a synonym of _woodfordi_." For the following reasons I agree with these authors: (1) _austini_ is known from only two specimens, both of which are apparently subadults; (2) _austini_ is reported to have a forearm 84 long and no interfemoral membrane, whereas _woodfordi_ has a forearm about 96 long and an interfemoral membrane that is only slightly developed; (3) specimens that agree in size and cranial characters with the type of _woodfordi_ but that lack an interfemoral membrane have been obtained; and (4) skulls of subadults of _woodfordi_ agree with the description of skulls of _austini_.

Sanborn (1931:19) reported that specimens of _Pteropus woodfordi_ were obtained at night, while feeding on young green coconuts. Lawrence (1945:62) reported that in the late afternoon a collector found individuals of _austini_ [= _woodfordi_] in the fronds of a coconut tree, apparently feeding on pollen shoots. Sanborn and Beecher (1947:388) have reported malaria (_Plasmodium_) in _P. woodfordi_ obtained on Guadalca.n.a.l. They suggested that malaria might have rendered one individual helpless because when it was found, on the ground, no wounds were evident and parasites were present in the blood.

[Ill.u.s.tration: FIG. 7. Distribution of _Pteropus woodfordi_ ([BW]) and _P. mahaga.n.u.s_ ([BC]). For names of islands see Fig. 2.]

=Pteropus mahaga.n.u.s= Sanborn

1931. _Pteropus mahaga.n.u.s_ Sanborn, Publ. Field Mus. Nat. Hist., Zool. Ser., 18:19, February 12, type from Santa Ysabel, also reported from Bougainville; 1954, Laurie and Hill, List of land mammals of New Guinea, Celebes and adjacent islands, p. 39, June 30.

_Specimens examined_ (one male and two females; one in alcohol).--Bougainville, in August and October, USNM 276972, USNM 277104-5.

_Measurements._--Measurements of one male and two females are, respectively, as follows: Length of head and body, 180, 204, 198; hind foot, 42, 38, 44; ear, 25, 23, 22; length of forearm, 134, 138, 140.

Measurements of the skull of the male and one female are, respectively, as follows: Greatest length of skull, 52.5, 55.8; condylobasal length, 50.9, 54.3; palatal length, 24.1, 26.0; zygomatic breadth, 28.9, 32.5; breadth across first upper molars, 14.4, 15.0; width of M1, 2.2, 2.2; length of maxillary tooth-row, 17.4, 18.4; length of mandibular tooth-row, 20.1, 21.4.

_Remarks._--Sanborn (1931:19-21) described _Pteropus mahaga.n.u.s_ on basis of six specimens, five from Santa Ysabel and one from Bougainville. The latter was in poor condition and only provisionally allocated to this species. The specimens examined by me (listed above) confirm the occurrence of _P. mahaga.n.u.s_ on Bougainville.

Sanborn (1931:20) described _mahaga.n.u.s_ as "similar to and about the size of [_Pteropus scapulatus_] from Australia, but lighter in color,"

and considered it, along with _P. woodfordi_, a member of the _Pteropus scapulatus_ group of Andersen (1912:402) and Tate (1942:336). I would judge, however, that _P. mahaga.n.u.s_ and _P. woodfordi_ are much more closely related to one another than to _P. scapulatus_ of Australia. The only significant characteristic that the latter has in common with the two species from the Solomons is small cheek-teeth. In fact, teeth of _scapulatus_ are relatively smaller than teeth of either _mahaga.n.u.s_ or _woodfordi_. Also, in _scapulatus_ the upper canines are widely separated due to lateral expansion of the palate at that point, whereas in _mahaga.n.u.s_ and _woodfordi_ the width across the upper canines is relatively much less.

=Dobsonia= Palmer

1898. _Dobsonia_ Palmer, Proc. Biol. Soc. Was.h.i.+ngton, 12:114, April 30.

1810. _Cephalotes_ (part) e. Geoffroy, Ann. du Mus. d'Hist. Nat., 15:104.