Forest dormice (Dryomys nitedula) occur in the Palearctic region. They are present throughout Europe and range as far south as northern Africa and as far east as Japan.

Biogeographic Regions: palearctic (Native )

Head and body length of forest dormice ranges from 80 to 130 mm. Tail length ranges from 60 to 113 mm. Body weights range from 18 to 34 g. Dryomys is considered to be very similar to Eliomys, but is smaller. The braincase of forest dormice is more rounded and the auditory bullae are smaller when compared with Eliomys.

Forest dormice are squirrel-like in appearance, with a grayish brown to yellowish-brown dorsum and buff white underside. They have a flat and bushy tail that is more uniform in color than Eliomys.

Range mass: 18 to 34 g.

Range length: 80 to 130 mm.

• Terrestrial

Forest dormice are found in dense forests, usually deciduous and mixed forests, as well as thickets at elevations of up to 3500 m. Forest dormice utilize cultivated areas such as gardens and also rocky meadows. They choose dense shrubbery or lower branches of trees in which to make a nest.

Range elevation: 3,500 (high) m.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: forest

Other Habitat Features: agricultural

Forest dormice are omnivores. They eat leaves as well as choice flowers, fruits, and nuts. They also eat arthropods, eggs, and young birds. Animal matter is observed to be preferred dietary item during the summer.

Animal Foods: birds; eggs; insects; terrestrial non-insect arthropods

Plant Foods: leaves; seeds, grains, and nuts; fruit

Primary Diet: omnivore

Forest dormice may play a role in controlling poulations of arthropods that make up a significant part of their diet. They also eat seeds and fruits, and therefore may aid in the dispersal of seeds. Because this species provides food for predators such as owls, forest dormice may have some positive impact on populations of these predators.

Ecosystem Impact: disperses seeds

Dryomys nitedula is nocturnal, occurs at low densities, and individuals are very careful to not travel away from brushy cover. These behaviors make these animals difficult prey to find. Remains of forest dormice have been found in the pellets of owl such as Strix aluco and Bubo bubo in eastern Europe.

Known Predators:

• tawny owls (Strix aluco)
• Eurasian eagle-owls (Bubo bubo)

Dryomys has been observed to emit a variety of vocalizations. Most notable of those is a delicate, melodious squeak that appears to function as an alarm call. Research on captive individuals has demonstrated that D. nitedula has the ability to emit repeated series of ultrasounds. The signals were given off by both sexes in situations suggesting a social character of the communication. These communications were entirely inaudible to the human ear.

Although not specifically reported for this species, it is likely that tactile, chemical, and visual signals are part of the repetoir of communication. Mammals typically use tactile communication during mating, conflict, and rearing of young. Chemical communication can be important in individual identification, as well as in reproductive contexts. Visual signals are often given, by means of body posturing, to indicate hostile or friendly intent.

Communication Channels: visual ; tactile ; acoustic ; chemical

Perception Channels: visual ; ultrasound

Dryomys nitedula can be expected to live up to 5.5 years in the wild.

Average lifespan

Status: wild: 5.5 years.

Average lifespan

Status: wild: 4.0 years.

Not much information is available on the mating system of this species.

The breeding season for forest dormice varies throughout the species' range. In Israel, the breeding season extends from March to December. On average, each female gives birth 2 to 3 times a year. In Europe, the breeding season lasts from May to August, and usually just one litter occurs each year. The gestation period is between 21 and 30 days. Usually 2 to 5 individuals are born per litter, although occassionally up to 7 may be possible.

Each offspring weighs approximately 2 g at birth. Eyes do not open until around day 16 of life, and independence from the mother is not achieved until the young are 4 to 5 weeks of age. In Europe the young will wait until after their first winter to mate.

Breeding interval: In Israel the species will breed 2 to 3 times per year. In Europe the species breeds only once per year.

Breeding season: In Israel, the mating season extends from March to December. In Europe the mating season occurs from May to August.

Range number of offspring: 2 to 7.

Range gestation period: 21 to 30 days.

Range time to independence: 4 to 5 weeks.

Average age at sexual or reproductive maturity (female): 1 years.

Average age at sexual or reproductive maturity (male): 1 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous

Average birth mass: 1.73 g.

Average number of offspring: 3.

There is little information available on the parental care of this speices. Neonates are altricial, and do not open their eyes until they are about 16 days old. Young are dependent upon their mother until they are 4 to 5 weeks of age. Until they are independent, it is likely that the mother provides them with food (milk), grooming, and protection. Male parental care has not been reported, but cannot be ruled out, either.

Parental Investment: no parental involvement; altricial ; pre-fertilization (Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female)

Dryomys nitedula is regarded as endangered in the Czech Republic and as rare in most other European countries. IUCN designated forest dormice as lower risk, but the species is not listed by CITES. The threat to the population stems mainly from the destruction of forest habitat throughout their range.

The UK has developed a National Dormouse Monitoring Programme, which exists primarily to monitor hazel dormice. Hazel dormice are a cherished child storybook star in England and Wales, but the program elements are a standard for all species of dormice. Researchers have placed dormouse nest boxes on trees in woodland areas where dormice have been known to occur, and return to those boxes to count, sex, and weigh the dormice. Research is done in order to form a database for the species and monitor the health of the population.

English Nature has been running a reintroduction program that has been reintroducing captive-bred dormice since 1994 to areas where populations were at one time plentiful. Also the English government has begun to award farmers incentives to replant hedgerows which are very important to the habitat of forest dormice. Such conservation efforts would also be helpful in maintaining populations of other species of dormice, such as D. nitedula.

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

Populations of D. nitedula have been known to cause economic damage by raiding fruit orchards and gnawing at the bark of coniferous trees.

Negative Impacts: crop pest

There was no specific data on the positive economic significance for humans of D. nitedula.