Animal Diversity Web

Ge­o­graphic Range

Pteromys momonga, also known as the Japan­ese fly­ing squir­rel, is found on Hon­shu and Kyushu Is­lands. (Nowak, 1999)

• Biogeographic Regions
• palearctic
  • native

• Other Geographic Terms
• island endemic

Habi­tat

The habi­tat of this species con­sists of bo­real ever­green forests. On a smaller spa­tial scale, they lo­cate their nests (com­posed of moss or lichen) at the junc­tion of a branch and the trunk of a tree, par­tic­u­larly pine or spruce. (Nowak, 1999)

• Habitat Regions
• temperate

• Terrestrial Biomes
• forest
• rainforest

Phys­i­cal De­scrip­tion

The head and body length of P. momonga is 120 to 228 mm, and the tail length is be­tween 108 and 127 mm. The mass of these an­i­mals has not been re­ported, and no sex­ual di­mor­phism has been de­scribed. Their col­oration is a sil­very to buffy gray on the dor­sal sur­face, and a buffy white on the ven­tral sur­face. The glid­ing mem­brane ex­tends from the an­kles to the wrists, but they lack a mem­brane be­tween the hind legs and the base of the tail. They blend so well with the col­oration of the tree bark that they prac­ti­cally be­come in­vis­i­ble. (Nowak, 1999)

• Other Physical Features
• endothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike

• Range length

  120 to 228 mm

  4.72 to 8.98 in

De­vel­op­ment

No species-spe­cific de­vel­op­ment in­for­ma­tion is avail­able, but the fol­low­ing is a gen­eral pat­tern in fly­ing squir­rels. The young squir­rel is naked at birth, with blood ves­sels and in­ter­nal or­gans vis­i­ble through the skin. The pup is born com­plet­ley help­less, re­ly­ing on its mother for food. After a week, the skin dark­ens and short hairs begin to de­velop. Some ba­bies can right them­selves at this age. At two weeks old, more fur de­vel­ops, the toes are sep­a­rated, and the ear canals begin to open. The in­fant is soon able to move its tail and fa­cial whiskers vol­un­tar­ily. At three weeks lat­eral hairs begin to de­velop on the tail and the baby re­sponds to loud noises. At four weeks, the baby is com­pletely furry, and the eyes open. They move about en­er­get­i­cally and sam­ple food that the mother brings. At five weeks they start some ex­plo­ration out­side of the nest (Wells-Gosling, 1985).

Re­pro­duc­tion

The mat­ing sys­tem of these an­i­mals has not been re­ported.

A pair of adults usu­ally shares a nest. There is a ges­ta­tion pe­riod of ap­prox­i­mately 4 weeks. Birth of the young oc­curs pre­dom­i­nantly in May, but in June or early July, a sec­ond lit­ter is often pro­duced. There can be a range of 1 to 5 young per lit­ter, with an av­er­age of 2 or 3. The young are weaned after 6 weeks. (Nowak, 1999)

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

• Breeding interval

  These animals apparently breed once or twice annually.

• Breeding season

  P. momonga is reported to breed from May through July.

• Range number of offspring

  1 to 5

• Average number of offspring

  2 or 3

• Average gestation period

  4 weeks

• Average weaning age

  6 weeks

De­tails of the parental be­hav­ior of this species have not been re­ported. Young sci­urids are typ­i­cally al­tri­cial. The mother nurses the young for ap­prox­i­mately six weeks, and pre­sum­ably grooms and oth­er­wise cares for them dur­ing that time. It is not known what role the male may play in parental care. (Nowak, 1999)

• Parental Investment
• altricial
• pre-weaning/fledging
  • provisioning
    • female

Lifes­pan/Longevity

No in­for­ma­tion was found specif­i­cally for P. momonga, but other fly­ing squir­rels usu­ally live 4 to 5 years. (Wells-Gosling, 1985)

Be­hav­ior

Japan­ese fly­ing squir­rels are strictly noc­tur­nal and silent in flight. They rarely re­main on the ground, in­stead spend­ing their time in the trees. Dur­ing the day, these an­i­mals can be found in their nests or in a hole in trees. They emerge at dusk, mov­ing quickly about the tree­tops. This is prob­a­bly a preda­tor-avoid­ance adap­ta­tion. Some­times many in­di­vid­u­als of the same sex are found in a sin­gle tree. The ex­cep­tion to this is dur­ing the mat­ing sea­son, when both sexes oc­cupy the tree. (Ando, et al., 1986; Nowak, 1999)

• Key Behaviors
• arboreal
• glides
• nocturnal
• motile
• social

Home Range

The home range size has not been re­ported for this species.

Com­mu­ni­ca­tion and Per­cep­tion

Data on ccom­mu­ni­ca­tion in P. momonga is lack­ing, but this species prob­a­bly re­lies mainly on vocal com­mu­ni­ca­tion, such as chit­ter­ing noises. This would make them like other fly­ing squir­rels.

Moth­ers keep their young in a tree nest for at least six weeks, and it is likely that there are some forms of tac­tile com­mu­ni­ca­tion oc­cur­ring in that con­text. (Wells-Gosling, 1985)

• Communication Channels
• tactile
• acoustic

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

The diet of Japan­ese fly­ing squir­rels con­sists of nuts, pine seeds, the buds and bark of cer­tain trees, fruits, and prob­a­bly some in­sects. Their forepaws may play only a sup­ple­men­tal role in hold­ing food, which was ex­hib­ited by a study done using bait to ob­serve how the species eats in com­par­i­son to oth­ers. The study also found that when the squir­rels were on a perch, they had to turn their bod­ies side­ways in order to bring food to the mouth. (Ando, et al., 1986)

• Primary Diet
• herbivore
  • frugivore
  • granivore
  • lignivore

• Animal Foods
• insects

• Plant Foods
• leaves
• wood, bark, or stems
• seeds, grains, and nuts
• fruit
• flowers

Pre­da­tion

Spe­cific preda­tors for P. momonga have not been re­ported. How­ever, as small, noc­tur­nal mam­mals, they are prob­a­bly sub­ject to pre­da­tion by owls.

Japan­ese fly­ing squir­rels posses sev­eral fea­tures which are adapted to avoid preda­tors. Their cryp­tic col­oration helps them blend into their en­vi­ron­ment, so that they are less eas­ily de­tected by preda­tors. They also lie so flat against the tree that they look like an in­con­spic­u­ous lump on the bark. It is thought that their er­ratic, quick move­ments help them to avoid preda­tors also. In ad­di­tion, they might use their glid­ing abil­ity to es­capre from preda­tors. (Nowak, 1999)

• Anti-predator Adaptations
• cryptic

Ecosys­tem Roles

Since P. momonga eats pine seeds, it most likely serves as a seed dis­perser for pine species. It may also be im­potant in local food webs. (Nowak, 1999)

• Ecosystem Impact
• disperses seeds

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Fly­ing squir­rels through­out the world have been mar­keted in the pet trade and used for their fur. (Wells-Gosling, 1985)

• Positive Impacts
• pet trade
• body parts are source of valuable material

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

This species does not ad­ver­s­ley af­fect hu­mans, since it re­sides in forested land­scapes where it sel­dom comes into con­tact with peo­ple.

Con­ser­va­tion Sta­tus

There hasn't been any analy­sis done to de­ter­mine bio­di­ver­sity or con­ser­va­tion for P. momonga.

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Migratory Bird Act

  No special status

• US Federal List

  No special status

• CITES

  No special status

Con­trib­u­tors

Nancy Shef­ferly (ed­i­tor), An­i­mal Di­ver­sity Web.

Tracy Watkins (au­thor), Hum­boldt State Uni­ver­sity, Brian Ar­bo­gast (ed­i­tor), Hum­boldt State Uni­ver­sity.

Ref­er­ences

Ando, M., S. Shi­raishi, T. Uchida. 1986. Feed­ing Be­hav­ior of Three Species of Squir­rels. Be­hav­iour, 95: 76-86.

Nowak, R. 1999. Walk­ers Mam­mals of the World, Sixth Edi­tion. Bal­ti­more: Johns Hop­kins Uni­ver­sity Press.

Wells-Gosling, N. 1985. Fly­ing Squir­rels. USA: Smith­son­ian In­sti­tute Press.