(Desmarest, 1820)
Fulvous Fruit bat
External characters (Table 2)
This bat resembles R. aegyptiacus , but averages smaller, sex for sex, with a forearm length of 80.6 mm (75-86 mm). The hind feet and thumbs are shorter, the latter usually less than 31 mm (measurement includes metacarpal, phalanx and claw (RL13). The second phalanx of the third digit is also shorter, usually less than 47 mm; it tends to exceed 51 mm in R. aegyptiacus . The muzzle is relatively short and slender (RL1). The pelage is soft, fine and silky, but differs from R. a. arabicus in its darker tone. It is fulvous brown on the crown of the head, back, flanks and throat; the belly is more greyish in the median area. According to Agrawal and Sinha, 1973, the baculum is dumbbell-shaped, its proximal end is ovoid and larger than the distal. The baculum of a specimen from Sri Lanka was small and peg-shaped (Fig. 3).
Cranial characters
The skull (Fig. 5) with a condylobasal length of 35.8 mm (33.5-37.7 mm) averages smaller and is usually more delicate than that of R. a. arabicus . The rostrum is generally more slender and tapered and the premaxillae tend to project more distinctly in front of the nasals. The mandible is relatively more slender and delicate.
Dentition
The dentition, (Fig. 4) with an average upper toothrow length (C-M2) of 14.2 mm (13.5-15.2 mm) is essentially similar to that of R. a. arabicus (BW1) but is usually smaller and more delicate. The cheekteeth are relatively narrow in relation to their length; this difference is most evident in M2 and m3.
Variation
The status of R. l. seminudus from Sri Lanka is unclear (RL2). According to Andersen, 1912 the fur of seminudus is markedly shorter than that of R. l. leschenaulti , with the nape and shoulders covered with such sparse and short hairs that they appear semi-naked; the pelage colour is lighter and the first premolar is often absent. This view was not accepted by Sinha, 1968; Sinha, 1980) who found considerable individual variation in all these characters (RL3). However Corbet and Hill, 1992 still listed seminudus as a distinct subspecies. Specimens from elsewhere in the subcontinent are referred to the nominate form R. l. leschenaulti . More research is required in this matter and more importantly in the relationship between leschenaulti and aegyptiacus . For as noted in the Taxonomic remarks of R. aegyptiacus , future research may show that leschenaulti and aegyptiacus are conspecific. In this case, specimens currently referred to R. l. leschenaulti would be assigned to R. aegyptiacus leschenaulti and those assigned to R. l. seminudus to R. a. seminudus . Males exceed females in size (Rookmaaker and Bergmans, 1981).
Taxonomic remarks
Agrawal and Sinha, 1973 and Agrawal and Bhattacharyya, 1977 recorded the smaller Rousettus amplexicaudatus from Tripura and Arunachal Pradesh in north-east India. However, Rookmaaker and Bergmans, 1981 who re-examined these specimens consider that they are referable to R. leschenaulti , based on the length of the maxillary cheekteeth row (c-m2) which measured 14.7 mm in all three specimens. This view was subsequently followed by Das, 1986a.