By Tracy Watkins
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)
These animals are found in the following types of habitat:
temperate .
Terrestrial Biomes:
forest ; rainforest .
Physical Description
(4.72 to 8.98 in; avg. 6.85 in)
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)
Some key physical features:
endothermic ; bilateral symmetry .
Sexual dimorphism: sexes alike.
Reproduction
These animals apparently breed once or twice annually.
P. momonga is reported to breed from May through July.
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 .
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, Shiraishi, and Uchida, 1986; Nowak, 1999)
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)
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, Shiraishi, and Uchida, 1986)
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)
Key ways these animals impact their ecosystem:
disperses seeds.
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.
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)
Ways that people benefit from these animals:
pet trade ; body parts are source of valuable material.
Conservation Status
IUCN Red List: [link]:
Lower Risk - Least Concern.
US Migratory Bird Act: [link]:
No special status.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
There hasn't been any analysis done to determine biodiversity or conservation for P. momonga.
Contributors
Tracy Watkins (author), Humboldt State University.
Brian Arbogast (editor), Humboldt State University.
Nancy Shefferly (editor), Animal Diversity Web Staff.
