Animal Diversity Web

Ge­o­graphic Range

Malay Penin­sula, Suma­tra, Java, Bor­neo, Philip­pines. Also recorded from the is­lands of Penang, Sin­ga­pore and Tioman.

• Biogeographic Regions
• oriental
  • native

Habi­tat

Naked bats roost in hol­low trees, caves, build­ings, rock crevices, and holes in the earth.

Phys­i­cal De­scrip­tion

The naked bat is a strik­ing mem­ber of the Molos­si­dae. It is vir­tu­ally hair­less, ex­cept for short, fine hairs on the head and tail mem­brane, and black, bristly hairs around the neck, on the first toe of the hind foot (prob­a­bly used for groom­ing) and on the throat sack, which pro­duces a strong-smelling se­cre­tion. Males se­crete the sub­stance by a se­ries of small pores, fe­males by a sin­gle large ori­fice (Lek­agul and Mc­Neely, 1977). Both sexes also pos­sess a pouch along the sides of the body, formed by a fold of skin that runs from the upper arm to the upper part of the leg. The pouches open to­wards the rear and the wings are pushed into them by the hind feet. In this way, the bat can move about rel­a­tively freely on all four limbs. C. torqua­tus has the thick­est jaws, widest face, and some of the broad­est-tipped wings in the en­tire fam­ily. The head is rel­a­tively large and broad with a well-de­vel­oped pos­te­rior sagit­tal crest. Un­like most Molos­si­dae, the ears are sep­a­rate, small and tri­an­gu­lar, and the lips are smooth. The muz­zle lacks a nose­leaf and the snout pro­jects well be­yond the bot­tom jaw. The thick, elas­tic skin is al­most black and con­tains many wrin­kles and folds. The thick tail pro­trudes well over half its length. The wings are at­tached to the mid­point of the back. The first toe of each hind foot is op­pos­able and equipped with a flat­tened nail rather than a claw. The den­tal for­mula is 1/1, 1/1, 1/2, 3/3 x 2 = 26. The upper in­cisors are ro­bust, short and pro­trude for­ward. There is a di­astema be­tween the upper in­cisor and ca­nine (Lek­agul and Mc­Neely, 1977). Head and body: 132-145 mm; tail: 56-71 mm. Weight: 167-196 grams.

• Other Physical Features
• endothermic
• bilateral symmetry

• Range mass

  167 to 196 g

  5.89 to 6.91 oz

• Range length

  115 to 145 mm

  4.53 to 5.71 in

Re­pro­duc­tion

C. torqua­tus usu­ally has two off­spring. The mam­mae are po­si­tioned near the open­ing of the pouch, which is pre­sent in both sexes and runs along the sides of the body. It was tra­di­tion­ally thought that the young were car­ried and nursed in the pouch. How­ever, ac­cord­ing to Nowak (1991) the young are prob­a­bly left in the roost when the par­ents leave on their evening flights.

• Key Reproductive Features
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • internal
• viviparous

• Average number of offspring

  2

Be­hav­ior

C. torqua­tus is gre­gar­i­ous, as roosts of nearly a thou­sand are found and a colony in a cave in Bor­neo to­taled 20,000 (Nowak, 1991). They leave their roost early in the evening, and feed quickly and di­rectly, more boldly than smaller bats which move cau­tiously to avoid preda­tors such as owls and bat hawks. They use echolo­ca­tion to hunt for food, and click­ing sounds are au­di­ble dur­ing echolo­ca­tion.

• Key Behaviors
• nocturnal
• motile
• social
• colonial

Com­mu­ni­ca­tion and Per­cep­tion

• Perception Channels
• tactile
• chemical

Food Habits

C. torqua­tus is in­sec­tiv­o­rous. The diet pri­mar­ily con­sists of ter­mites and other in­sects, hunted ei­ther over clear­ings and fields or above the for­est canopy. Wastes are elim­i­nated as both feces and oral pel­lets.

• Primary Diet
• carnivore
  • insectivore

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Since C. torqua­tus live in large num­bers they con­sume vast quan­ti­ties of in­sect pests.

• Positive Impacts
• controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Farm­ers in Malaya be­lieve that C. torqua­tus feeds on paddy, gath­er­ing grain from ripe ears to store in the roost. How­ever, it is more likely that rats, which share this habi­tat with bats, are re­spon­si­ble for the grain found in­side hol­low trees (Med­way, 1978).

Con­ser­va­tion Sta­tus

Listed as Lower Risk/Near Threat­ened by the In­ter­na­tional Union of Con­ser­va­tion of Na­ture and Nat­ural Re­sources (IUCN).

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

Other Com­ments

For ex­cel­lent pho­tos of C. torqua­tus, visit Walker's Mam­mals of the World on­line at

http://​www.​press.​jhu.​edu/​books/​walker/​chiroptera/​images/​image.​chiroptera.​molossidae.​cheiromeles.​html

Con­trib­u­tors

Paul Thom­son (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, On­drej Pod­laha (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

For­est De­part­ment Sarawak, Malaysia, Au­gust 15, 2001. "Naked Bat (Cheirome­les torqua­tus)" (On-line). Ac­cessed Oc­to­ber 6, 2001 at http://​www.​forestry.​sarawak.​gov.​my/​forweb/​wildlife/​mgmt/​tpa/​nbat.​htm.

Free­man, P. March 31, 1981. A Mul­ti­vari­ate Study of the Fam­ily Molos­si­dae (Mam­malia, Chi­roptera): Mor­phol­ogy, Ecol­ogy, Evo­lu­tion. FIEL­DIANA Zo­ol­ogy, New Se­ries, No. 7: 87-88.

Hill, J., J. Smith. 1984. Bats: A Nat­ural His­tory. Lon­don: British Mu­seum (Nat­ural His­tory).

Hilton-Tay­lor, C. 2000. "2000 IUCN Red List of Threat­ened Species" (On-line). Ac­cessed Oc­to­ber 11, 2001 at http://​www.​redlist.​org/​search/​details.​php?​species=4601.

Lek­agul, B., J. Mc­Neely. 1977. Mam­mals of Thai­land. Bangkok: Sa­hakarnbhat.

Med­way, L. 1978. The Wild Mam­mals of Malaya (Penin­su­lar Malaysia) and Sin­ga­pore. Kuala Lumpur: Ox­ford Uni­ver­sity Press.

Nowak, R. 1991. Walker's Mam­mals of the World. Bal­ti­more and Lon­don: The Johns Hop­kins Uni­ver­sity Press.

Sarawak For­est De­part­ment and WCS, June 23, 2001. "Lords of the Night" (On-line). Ac­cessed Oc­to­ber 6, 2001 at http://​www.​mered.​org.​uk/​saraweb/​animals/​Bats.​htm.