Scotonycteris zenkeri, Matschie, 1894

Don E. Wilson & Russell A. Mittermeier, 2019, Pteropodidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 16-162 : 81

32.

Zenker’s Fruit Bat

Scotonycteris zenkeri

French: Scotonyctére de Zenker / German: ZenkerHarlekinflughund / Spanish: Scotonicterio de Zenker

Taxonomy. Scotonycteris zenkeri Matschie, 1894 ,

“Yaunde [= Yaoundé] Station,” Centre Region, Cameroon.

Until recently, S. zenkeri was considered to have a relatively wide but disjunct distribution; however, mtDNA analyses distinguished four clades that resulted in raising subspecies occidentalis to the species level for the westernmost populations and description of a new species for the eastern populations ( S. bergmansi ). Populations from Nigeria might belong either to S. zenkeri or S. occidentalis , additional molecular data are needed. Identity of specimens from Bioko Island (currently assigned to bedfordi) needs to be confirmed. Existing karyological data belong to a bat from Gabon, which is currently assigned to S. bergmansi . Two subspecies recognized.

Subspecies and Distribution.

S.z.zenkeriMatschie,1894—CameroonandpossiblyNigeria,butfurtheranalysisofmoleculardataisneededtoconfirmitspresenceinlattercountry.

S. z. bedfordi Thomas, 1904 — Bioko I.

Descriptive notes. Head-body 65-85 mm (tailless), ear 12-17 mm, hindfoot 11- 14 mm, forearm 47-55 mm (on average females slightly longer); weight 16-24 g. Zenker’s Fruit Bat has white face markings on forehead and posterior corners of eyes; partially pale or white lips, especially around corners; short and slender muzzle; large dark brown eyes; naked ears with rounded tips, dark brown with lighter base, no basal ear patches; and moderately expansible lips. There are no epaulettes on adult males; dorsum is generally medium rusty brown to sepia-brown and speckled; hairs have dark brown basal one-third, pale gray middles, and rusty brown tips; pelage is dense, soft, woolly, and mid-dorsally 9-10 mm long. Central lower chest and belly are whitish to pale gray; flanks are medium to dark brown, not as sharply contrasting as in Hayman’s Fruit Bat ( S. occidentalis ); and pelage of underparts is shorter and sparser than dorsum, with stiff hairs on chest and belly. Wings have claw on second digit; membranes from sides of body are light brown to dark greenish brown and reticulated, attaching to first toes; finger joints are not yellowish; calcar is present. Skull is short and delicate; forehead region is almost straight; rostrum is relatively short; braincase is rounded; zygomatic width is relatively small, with relatively lightly built arches; palate is weakly arched; there are four thick, smooth palatal ridges, followed by 6-9 very thin, serrated, and irregular ridges; ridges 1-3 are not divided, and ridge 4 is occasionally divided in middle; bony palate extends clearly beyond posterior teeth; and post-dental palate has straight, converging lateral margins. Dental formula for all species of Scotonycterisis12/2,C1/1,P2/3, M 1/2 (x2) = 28. Upper incisors are relatively short and hardly curved, with blurred inner groove and without secondary cusps or serrated inner edges; C! is long and recurved; and premolars and molars are rounded, almost oval in transverse section, with relatively weak cusps.

Habitat. [Lowland and montane forests, including untouched and disturbed rainforests, forest fringes, cultivated clearings over lowland forests (Bioko Island) from sea level up to elevations of ¢. 1100 m. Zenker’s Fruit Bat is never in large cleared areas or far from forests.

Food and Feeding. Zenker’s Fruit Bat is presumably frugivorous.

Breeding. Pregnant Zenker’s Fruit Bats were captured in February in south-western Cameroon and October on Bioko Island.

Activity patterns. No information.

Movements, Home range and Social organization. Zenker’s Fruit Bat usually roosts alone.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Zenker’s Fruit Bat has a wide distribution and apparently large population, and it is unlikely to be declining fast enough to be listed in a higher category. Nevertheless,itis rarely encountered, and current status needs to be reviewed because this assessment also includes populations currently assigned to Hayman’s Fruit Bat and Bergmans’s Fruit Bat ( S. bergmansi ). Habitat loss from logging and mining activities and conversion to agricultural use is a major threat.

Bibliography. Bergmans (1979a, 1991), Bergmans, Fahr et al. (2017), Eisentraut (1960a, 1973), Fahr (2013c), Hassanin et al. (2015).

Figures

32. Zenker’s Fruit Bat (Scotonycteris zenkeri), 33. Hayman’s Fruit Bat (Scotonycteris occidentalis), 34. Bergmans’s Fruit Bat (Scotonycteris bergmansi), 35. Short-palated Fruit Bat (Casinycteris argynnas), 36. Pohle’s Fruit Bat (Casinycteris ophiodon), 37. Campo-Ma’an Fruit Bat (Casinycteris campomaanensis), 38. Lesser Dawn Bat (Eonycteris spelaea), 39. Greater Dawn Bat (Eonycteris major), 40. Philippine Dawn Bat (Eonycteris robusta), 41. Geoffroy’s Rousette (Rousettus amplexicaudatus), 42. Bare-backed Rousette (Rousettus spinalatus), 43. Leschenault’s Rousette (Rousettus leschenaultin), 44. Linduan Rousette (Rousettus linduensis), 45. Sulawesi Rousette (Rousettus celebensis), 46. Egyptian Rousette (Rousettus aegyptiacus), 47. Malagasy Rousette (Rousettus madagascariensis), 48. Comoro Rousette (Rousettus obliviosus), 49. Long-haired Fruit Bat (Stenonycteris lanosus)

Subspecies and Distribution. S.z.zenkeriMatschie,1894—CameroonandpossiblyNigeria,butfurtheranalysisofmoleculardataisneededtoconfirmitspresenceinlattercountry. S. z. bedfordi Thomas, 1904 — Bioko I.