(Blyth, 1851)
Tickell's bat
External characters (Table 107)
This is a relatively large Vespertilionid bat with an average forearm length of 54.9 mm (50.0-60.4 mm). The muzzle is broad and blunt, swollen on the sides and essentially naked anteriorly. The forehead is broad and thickly haired. The ears are yellowish-brown and situated far apart; they are moderately large, thick, fleshy; the anterior border is convex, the tip broadly rounded. The tragus of each ear is about half the length of the pinna; it is crescent shaped and with rather a blunt tip; the antitragus is well developed and partly concealed by short fur. The wings are moderately broad and rather long. The forearms, metacarpals and legs are naked and flesh-coloured; the membranes between them are black; the interfemoral membrane is light reddish-brown darkening to almost black, towards the outer margin. The pelage is moderately short and dense. It varies in colour on the dorsal surface from light greyish-yellow to bright golden-brown, sometimes with rather a rufous tinge to the tips of the hairs; the hair bases are dark grey. The ventral surface is lighter and greyer and the hairs shorter. The baculum has a simple shaft which is deflected downwards anteriorly; its tip is not thickened; the base is expanded and bilobate (Fig. 237).
Cranial characters
The skull (Fig. 238) is robust with an average condylo-canine length of 18.3 mm (17.2-19.6 mm). The rostrum is broad, its breadth equal to that of the braincase; the postorbital region is sharply constricted towards the postorbital constriction. The narial emargination is V-shaped but with a rounded apex. The palate is broad and with its post-palatal extension short. The basisphenoid pits are deep and clearly defined. The braincase is relatively narrow with the posterior sagittal crest and lambdoid crests well developed. The zygomata are slender. The mandible is robust, with well developed coronoid processes.
Dentition
- Upper toothrow length (C-M3) averages 7.7 mm (7.1-8.2 mm) in length. The first upper incisor (I2) is massive, canine-like, unicuspid and with a distinct cingulum (Fig. 239). The second (I3) is compressed between I2 and the canine; it is slightly intruded, ovate in shape with a wide, basin-like cingulum and a three-faced cusp. The canine is robust and unicuspid. The small upper premolar (PM2) is absent. The large premolar (PM4) is robust. M3 has a reduced metastyle and is about two-thirds the crown area of M1.
- The three lower incisors are tricuspidate and imbricated. The first lower premolar (pm2) is reduced, it is about one third the height and half the crown area of the second (pm4). The talonid of m3 is reduced.
Variation
Specimens from Sri Lanka and the Andaman Islands average smaller and are darker than those from the Indian mainland; they are more reddish brown dorsally, especially posteriorly (Hill, 1976a). However, to date all have been referred to the nominate race H. t. tickelli .