Animal Diversity Web

Ge­o­graphic Range

Ptero­pus dasy­mal­lus (Ryukyu fly­ing-fox) range from the Ryukyu is­lands of Japan (Kuchi­no­er­abu, Takara, Ok­i­nawa, Ishi­gaki, Iri­omote, Hatoma, Obama, Yon­akuni and some smaller is­lands) through parts of Tai­wan (Kashoto Is­land, east coast Tai­wan, and the Daito Is­lands). (Thatcher, 2004; Yoshiyuki, 1989)

• Biogeographic Regions
• oriental
  • native

• Other Geographic Terms
• island endemic

Habi­tat

Ryukyu fly­ing-foxes use forests for day­time roost­ing.

• Terrestrial Biomes
• forest
• rainforest

Phys­i­cal De­scrip­tion

Ryukyu fly­ing-foxes are in the sub­or­der Megachi­roptera. Key char­ac­ter­is­tics of this sub­or­der are that they have a well de­vel­oped pre­max­il­lary bone, a pos­tor­bital process is pre­sent, they lack a tra­gus and a nose­leaf, and their teeth are adapted for eat­ing fruit. There are 5 sub­species of Ryukyu fly­ing-foxes. They are P. d. daitoen­sis (Daito fruit bat), P. d. dasy­mal­lus (Erabu fruit bat), P. d. for­mo­sus (Tai­wanese fruit bat), P. d. in­opina­tus (Orii's fruit bat), and P. d. yayeya­mae (Yaeyama fruit bat). There are some char­ac­ter vari­a­tions among the sub­species. Ptero­pus dasy­mal­lus daitoen­sis has brown wings and a yel­low belly and back. The sides of the back are brown. The body is 221 mm long and fore­arm length 134 mm. Ptero­pus dasy­mal­lus dasy­mal­lus is the largest in size and dark­est in color of the sub­species. The fur col­oration con­sists of a black­ish head and face, body is usu­ally dark brown to black, and a cream col­ored area around neck. The fore­arm mea­sured at around 137 mm. Ptero­pus dasy­mal­lus for­mo­sus is thought to be ex­tinct in the wild. Ptero­pus dasy­mal­lus in­opina­tus has a brown muz­zle, and it has a patch of darker fur that in­ter­rupts the white col­lar around its neck. Ptero­pus dasy­mal­lus in­opina­tus has an ex­posed lacrimal fora­men. Ptero­pus dasy­mal­lus yayeya­mae is the small­est in size among the 4 wild sub­species. The fur color varies on the dor­sal and ven­tral sides of this sub­species. The head is usu­ally brown and the neck a cin­na­mon color. (Thatcher, 2004; Yoshiyuki, 1989)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike

• Average mass

  435 g

  15.33 oz

Re­pro­duc­tion

Ptero­pus dasy­mal­lus have low re­pro­duc­tive rates. In most fruit bats fe­males don't give birth for the first time until they are one or two years old (Mick­le­burgh et al. 1992). One young is born at a time with a ges­ta­tion pe­riod of 4 to 6 months. In P. d. daitoen­sis mat­ing takes place be­tween No­vem­ber and early Jan­u­ary and birth be­tween May and June (Thatcher 2004). (Mick­le­burgh, et al., 1992; Thatcher, 2004)

• Key Reproductive Features
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• viviparous

• Breeding season

  Mating takes place between November and early January

• Range number of offspring

  1 (low)

• Average number of offspring

  1

• Range gestation period

  4 to 6 months

• Range age at sexual or reproductive maturity (female)

  1 to 2 years

Lifes­pan/Longevity

• Average lifespan
  Status: captivity

  24 years

  AnAge

Be­hav­ior

Ptero­pus dasy­mal­lus roost in trees. The sub­species P. d. daitoen­sis may roost singly, in small groups, or even large camps. This sub­species also changes roost­ing sites (Thatcher 2004). Ptero­pus often form large groups on branches (Mick­le­burgh et al. 1992). The other sub­species live in colonies and usu­ally stay at the same roost­ing sites. (Thatcher 2004, Species Under Threat 1998) ("Species Under Threat", 2000; Mick­le­burgh, et al., 1992; Thatcher, 2004)

• Key Behaviors
• arboreal
• nocturnal
• motile
• colonial

Com­mu­ni­ca­tion and Per­cep­tion

• Communication Channels
• tactile
• acoustic
• chemical

• Other Communication Modes
• pheromones

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Ptero­pus dasy­mal­lus feeds al­most en­tirely on plants and their prod­ucts. Fruit makes up the bulk of the diet. Figs seem to be one of the an­i­mal's fa­vorites. Other plant prod­ucts that are eaten are the flow­ers and leaves. Flow­ers are eaten in the spring and leaves year round. In­sects may also be a part of the diet of this species in the sum­mer and au­tumn. One study showed that P. d. dasy­mal­lus has a more di­verse diet than any other pteropo­did bats ever stud­ied. Their diet in­cludes bark, 17 species of fruit, nine species of leaves, five species of flow­ers, and eight species of in­sects on Kuchi­no­er­abu Is­land. (Thatcher, 2004; Thatcher, 2004)

• Primary Diet
• herbivore
  • folivore
  • frugivore
• omnivore

• Animal Foods
• insects

• Plant Foods
• leaves
• fruit
• flowers

Ecosys­tem Roles

Ryukyu fly­ing-foxes are eco­nom­i­cally im­por­tant be­cause they pol­li­nate wild and com­mer­cial plants. ("Species Under Threat", 2000)

• Ecosystem Impact
• disperses seeds
• pollinates

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

The 5 sub­species pol­li­nate and dis­perse seeds im­por­tant to the tim­ber in­dus­try, food crops, and some med­i­c­i­nal plants. ("Species Under Threat", 2000)

• Positive Impacts
• pollinates crops

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Ptero­pus dasy­mal­lus do eat com­mer­cial fruit crops.

Con­ser­va­tion Sta­tus

De­for­esta­tion, hunt­ing, and ty­phoons are threats to pop­u­la­tions of P. dasy­mal­lus. Clear­ing of for­est for agri­cul­ture takes away roost­ing and food sup­plies for these bats. Ptero­pus dasy­mal­lus for­mo­sus is now be­lieved to be ex­tinct in the wild. The ex­tinc­tion of this sub­species in the wild is be­lieved to have been caused by hunt­ing and de­for­esta­tion (Thatcher 2004). Ty­phoons have a greater af­fect on for­est struc­ture be­cause of de­for­esta­tion. Smaller patches of trees are then more eas­ily knocked down by the wind leav­ing less and less habi­tat. Re­pro­duc­tive fac­tors also lead to con­ser­va­tion prob­lems. Ryukyu fly­ing-foxes have a low re­pro­duc­tive rate, mak­ing them un­able to re­cover quickly after pop­u­la­tion de­clines. (Thatcher 2004, Mick­le­burgh et al. 1992, Species Under Threat 1998). ("Species Under Threat", 2000; Mick­le­burgh, et al., 1992; Thatcher, 2004)

• IUCN Red List

  Near Threatened
  More information

• IUCN Red List

  Near Threatened
  More information

• US Federal List

  No special status

• CITES

  Appendix II

Con­trib­u­tors

Brian Putz (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Phil Myers (ed­i­tor), Mu­seum of Zo­ol­ogy, Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

2000. "Species Under Threat" (On-line). Ac­cessed 01/07/04 at http://​www.​wcmc.​org.​uk/​species/​data/​species_​sheets/​ryukyu-.​htm.

Mick­le­burgh, S., A. Hut­son, P. Racey. 1992. Old World Fruit Bats An Ac­tion Plan for their Con­ser­va­tion. Ox­ford, UK: In­for­ma­tion Press.

Thatcher, O. 2004. "Re­gional Con­ser­va­tion Is­sues, Japan and Tai­wan" (On-line). Lubee Bat Con­ser­vancy. Ac­cessed 01/07/04 at http://​www.​lubee.​org/​about-reg-japan.​aspx.

Yoshiyuki, M. 1989. A Sys­tem­atic Study of the Japan­ese Chi­roptera. Tokyo, Japan: Na­tional Sci­ence Mu­seum.