Balionycteris seimundi, Kloss, 1921

Don E. Wilson & Russell A. Mittermeier, 2019, Pteropodidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 16-162 : 73

20.

Malayan Spotted-winged Fruit Bat

Balionycteris seimundi

French: Cynoptéere de Seimund / German: Malaya-Fleckenkurznasenflughund / Spanish: Balionicterio de Seimund

Taxonomy. Balionycteris maculata seimundi Kloss, 1921 ,

“junction of the Tahan and Teku Rivers at the foot of Gunong Tahan, Pahang,” Peninsular Malaysia .

Important (12%) genetic distance between the Bornean form (formerly the nominate subspecies of B. maculata ) and the Peninsular Malaysian specimens (formerly assigned to B. m. seimundi ) indicate recognition at species level of seimundi . Specimens from Sumatra and islands of the south-western Riau Archipelago also differ morphometrically from those of Kalimantan and were assigned to B. sesmundi. All literature on Balionycteris from Peninsular Malaysia should be referred to as B. seimundi . Monotypic.

Distribution. Malay Peninsula from S Thailand and Sumatra, including SW Riau Archipelago (Bintan, Durian, and Galang Is).

Descriptive notes. Head-body 56-66 mm (tailless), ear 10-11 mm, hindfoot 6-3 7- 5 mm, forearm mean 40- 9 mm (adult males) and 41- 9 mm (adult females); weight 9-14 g (male mean 11- 8 g, female mean 11- 9 g). Head of the Malayan Spotted-winged Fruit Bat is rounded, with short muzzle, sparse haired, and dark brown skin; nostrils are shortly tubular and divergent; philtrum is divided by left and right grooves from base of corresponding nostril down to upper lip; and lower lip pads are large and fused. White spot of bare skin occurs in lacrimal. Eyes are large and bulging; iris is chocolate-brown to dark brown. Ears are short and rounded, and pinnae are dark brown, with slightly swollen white spot at bases and small tubercles on dorsal surfaces. Genal vibrissae form line of swollen follicles from mouth commissure backward. Head pelage is short, soft, velvety, blackish brown, continuing onto nape; dorsum has longer, wavier hairs and is dark brown. Uropatagium is broad on sides and narrow and hairy at center, and calcar short. Gland is present on throat of males. Chest and belly are light gray and softly haired; sides of neck are inconspicuously yellowish. Wing membranes attach to first toe and are dark grayish brown, almost black in some individuals, flecked with white; and characteristically, all wing digit joints are white and slightly swollen. Skull lacks basicranial deflection and is very small and lightly built. Laterally, rostrum is short, gently sloping into forehead; orbit is very large; zygomatic rootis slightly above upper alveolar line; zygoma is thin and arched posteriorly, and braincase is round. Dorsally, rostrum is broad; there is no postorbital foramen; postorbital processes are moderately developed and pointed, directed posterolaterally; paranasal recesses are inflated and posteriorly extended to base of left and right temporal lines, which are low and do not join to form a sagittal crest; there is almost no postorbital constriction; braincase almost rounded; nuchal crest is barely obvious; and zygomatic arches are moderately wide. Ventrally, palate is flat; tooth rows are lightly arched; post-dental palate is long and moderately converging, with straight caudal edge; palatine spine is inconspicuous and connected to sphenoid crest; and ectotympanic is small and wider anteriorly and internally edged by ribbon-like entotympanic. Mandible is thin, sloping into low coronoid with rounded tip; condyle is small and level with lower alveolar line; and angle is distinct and round. Upper dentition has two pairs of tiny incisors; C' is small and slightly decurved; P' is a spicule; next premolar (P°) is large and triangular; P* is low; molars are low, very small, and rectangular in occlusal outline; and M? is tiny and atavistic. Lower dentition has incisors that correspond to I, (I, absent), C,is very small, P| is peg-like, next premolar (P,) is large, posterior cheekteeth decrease in height and are rectangular, and M, minute. Diploid number is 2n = 24.

Habitat. Primary lowland rainforests, mangrove forests, and disturbed secondary forests up to elevations of ¢. 1500 m. The Malayan Spotted-winged Fruit Bat most frequently uses understories but also can be found ¢. 22 m aboveground.

Food and Feeding. The Malayan Spotted-winged Fruit Bat is a year-round, long-term resident frugivore that uses plants with widely different fruiting strategies from understory species with slow sequential ripening of a few fruits with extended (greater than two months) phenology to large trees with abundant, ephemeral (less than two weeks) crops. In Peninsular Malaysia, diet includes fruits of at least 14 genera in ten families. Fruits typically are small (0-5— 4-5 g) and green or yellow-green. Small groups forage in forest understories.

Breeding. The Malayan Spotted-winged Fruit Bat is seasonal polyestrous and polygynous. Gestation is c.135 days;litter size one. Females give birth twice a year, with most births in June-November. Young weigh 3-5 g at birth, with eyes closed and ears folded. Lactation lasts at least 40 days, occasionally up to 80 days. Young start to fly when they weigh 8 g and have forearm length of 36 mm. Sex ratio in adults is female biased (1:2-1). Adult size and sexual maturity are reached after six months, with first litter of females at c.10 months old.

Activity patterns. Female Malayan Spotted-winged Fruit Bats leave day roosts at dawn and forage at feeding sites all night. Males frequently return to day roosts to defend them between feeding bouts. Day roosts are tents built by males as small cavities modified in existing vegetation or social-insect nests. Root masses of epiphytic ferns ( Asplenium , Aspleniaceae ) and ginger ( Hedychium , Zingiberaceae ) are excavated to form a small, smooth semi-spherical cavity open from below; active ant nests ( Crematogaster ) and abandoned arboreal termite nests (Bulbitermes) are modified in similar ways.

Movements, Home range and Social organization. The Malayan Spotted-winged Fruit Bat is resident throughout the year and forages within 1 km of day roosts. Males roost alone or form harems with up to nine females and their dependent young. Males actively defend their tents from competing bachelor males. Females switch roost frequently and sequentially mate with different males.

Status and Conservation. Not assessed on The IUCN Red List. The Malayan Spottedwinged Fruit Bat was included in the Bornean Spotted-winged Fruit Bat ( B. maculata ), which was classified as Least Concern. It is widespread, abundant, and usually the most abundant fruit bat in the understory. It tolerates forest disturbance, but it depends on forest structure so it can be locally threatened by changes in land use (e.g. deforestation for agriculture).

Bibliography. Baker & Thomas (2016), Giannini & Simmons (2007a), Hodgkison (2001), Hodgkison & Kunz (2006), Hodgkison et al. (2003, 2004b), Khan et al. (2008), Kingston et al. (2006), Olson et al. (2001), Pounsin et al. (2018), Yong et al. (1973).

Figures

15. Brooks's Dayak Fruit Bat (Dyacopterus brooksi), 16. Common Dayak Fruit Bat (Dyacopterus spadiceus), 17. Philippine Large-headed Fruit Bat (Dyacopterus rickarti), 18. Blanford’s Fruit Bat (Sphaerias blanfordi), 19. Bornean Spotted-winged Fruit Bat (Balionycteris maculata), 20. Malayan Spotted-winged Fruit Bat (Balionycteris seemundi), 21. Bornean Pygmy Fruit Bat (Aethalops aequalis), 22. Common Pygmy Fruit Bat (Aethalops alecto), 23. Common Swift Fruit Bat (Thoopterus nigrescens), 24. Suhaniah’s Swift Fruit Bat (Thoopterus suhaniahae), 25. Mindanao Pygmy Fruit Bat (Alionycteris paucidentata), 26. Fischer’s Pygmy Fruit Bat (Haplonycteris fischeri), 27. Luzon Pygmy Fruit Bat (Otopteropus cartilagonodus), 28. Salim Ali’s Fruit Bat (Latidens salimaliz), 29. Sundaic Black-capped Fruit Bat (Chironax melanocephalus), 30. Sulawesi Black-capped Fruit Bat (Chironax tumulus), 31. Lucas’s Short-nosed Fruit Bat (Penthetor lucasu)

Distribution. Malay Peninsula from S Thailand and Sumatra, including SW Riau Archipelago (Bintan, Durian, and Galang Is).