Part 2 (1/2)

Family PTEROPODIDAE

Subfamily Pteropodinae

Rousettus Gray

1821. _Rousettus_ Gray, London Medical Repository, 15:299, April 1.

1843. _Xantharpyia_ Gray, List of species ... British Museum, p. 37.

1852. _Cynonycteris_ Peters, Reise nach Mossambique, p. 25.

The genus _Rousettus_ occurs throughout the tropical regions of the Old World, and in the Solomons is readily distinguished from all other megachiropteran genera by having both a small claw on the second digit and free caudal vertebrae. The oriental species have been divided into two groups on the basis of size (Tate, 1942:344). The subspecies _Rousettus amplexicaudatus hedigeri_ appears to be the sole representative of this genus in the Solomon Islands. Prior to 1953, several workers (Thomas, 1887b:323, 1888b:475; Matschie, 1899:68; Sanborn, 1931:11) used the name _Rousettus amplexicaudatus brachyotis_ for it, but Pohle (1953) suggested that the specimens from the Solomons recorded by earlier workers were _R. a. hedigeri_ named by him on the basis of the specimen that he saw from Bougainville.

=Rousettus amplexicaudatus=

_Rousettus amplexicaudatus_ has at least three subspecies, one of which is endemic to the Solomon Islands. The species is wide-ranging, being known from as far west as Thailand (Ellerman and Morrison-Scott, 1966:93) and as far east as the Solomons.

[Ill.u.s.tration: FIG. 3. Distribution of _Rousettus amplexicaudatus hedigeri_. For names of islands see Fig. 2.]

=Rousettus amplexicaudatus hedigeri= Pohle

1953. _Rousettus amplexicaudatus hedigeri_ Pohle, Z. Saugetierk., 17:127, October 27, type from Bougainville.

1887. _Cynonycteris brachyotis_, Thomas, Proc. Zool. Soc. London, p. 323, March 15; 1888, Thomas, Proc. Zool. Soc. London, p. 475, December 4, from Fauro.

1889. _Xantharpyia brachyotis_, Matschie, Die Megachiroptera ...

naturkunde, p. 68, from Guadalca.n.a.l.

1912. _Rousettus brachyotis_, Andersen, Catalogue of the Chiroptera ... British Museum, 1:809; 1931, Sanborn, Publ. Field Mus. Nat.

Hist., Zool. Ser., 18:11, February 12, from Santa Ysabel.

_Specimens examined_ (20 males and 21 females; all in alcohol; ten crania extracted and cleaned).--Guadalca.n.a.l in May, 23863, 23915; Fauro in April, 23804-5; Malaita in June, 24079; Choiseul in March, 23563-4, 23616, 23627, 23630, 23632-3, 23642, 23658, 23663-4, 23680, 23692-3, 23713, 23722; Kolombangara in January and February, 23343, 23366, 23382-4, 23389-90, 23408-9, 23424, 23455, 23471-4, 23501.

_Measurements._--Average and extreme external measurements of 13 males and 18 females are, respectively, as follows: Length of head and body, 104.4 (99-118), 108.6 (104-117); tail vertebrae, 16.8 (13-19), 17.6 (15-24); hind foot, 18.0 (16-19), 16.2 (12-18); ear, 15.9 (15-17), 15.0 (14-16); length of forearm, 70.1 (66.0-74.1), 68.1 (65.0-69.1). Average and extreme measurements of skulls of five males and five females are, respectively, as follows: Greatest length of skull, 33.2 (33.0-33.7), 31.5 (30.9-32.1); condylobasal length, 31.3 (30.9-31.9), 30.1 (29.3-30.8); palatal length, 14.0 (13.3-14.8), 13.3 (13.0-13.7); zygomatic breadth, 20.8 (19.8-21.8), 19.4 (18.7-20.8); length of maxillary tooth-row, 11.0 (10.9-11.3), 10.3 (10.1-10.6); length of mandibular tooth-row, 12.6 (12.4-12.9), 11.8 (11.7-12.2).

_Remarks._--The specimens from Choiseul, Kolombangara, and Malaita islands provide new records of distribution for _Rousettus amplexicaudatus hedigeri_ (Fig. 3). It was described as smaller than _R.

a. brachyotis_ Dobson, which is known from New Guinea, Amboina, and the Bismarck Archipelago (Pohle, 1953:127-128). Andersen (1912:809) gave the range of length of forearm in _R. a. brachyotis_ as 73-81, whereas Pohle (1953:127) gave the length of forearm of the type specimen of _R. a.

hedigeri_ (adult male) as 67. Measurements of specimens examined by me indicate that _hedigeri_ occurs throughout the Solomon Islands. Cranial measurements of my specimens and Pohle's type are less than those of _R.

a. brachyotis_ (see Andersen, 1912:48).

Sanborn (1931:11) noted that the forearms of three males examined by him were longer than that of a female. Mean and range for length of forearm of males and females listed herein, respectively, are 70.1 (66.0-74.1) and 68.1 (65.0-69.1). Also, each of seven cranial measurements taken by me averaged more in males than in females. Sagittal and lambdoidal crests are more prominent in males than in females.

TABLE 1. A Summary of Breeding Data for Females of _Rousettus amplexicaudatus hedigeri_ Collected December to June.

===========+===========+==============+===========+=============

Total

Number

Number of MONTH

number

adult [F][F]

Number

immature

collected

collected

lactating

individuals -----------+-----------+--------------+-----------+------------- December

3

3

3

0 January

11

11