A young wood mouse in hand
Fact file
Latin name
Apodemus sylvaticus
Threat status
Least Concern (Global)
Least Concern (Europe)
Least Concern (UK)
Etymology
Apodemus comes from Ancient Greek, meaning “having gone away from home”. Meanwhile, sylvaticus is latin, meaning “amidst the trees” and relates to woods as their primary habitat and their ability to climb trees.
Identifying features
Wood mice are reddish-brown on top with a pale grey or white underbelly. They sometimes have a streak of yellow/orange on their chests, but can be distinguished from yellow-necked mice as this mark does not form a collar touching the brown fur.
They can be differentiated from house mice as they are more red-brown than grey brown, have larger ears and a longer tail. They also do not smell as strongly!
For more image see our camera trap gallery.
Habitat
As their name suggests woodland is the primary habitat for wood mice, and they can be found in both coniferous and broad-leaved woodland. They are also commonly found in hedgerows and gardens, they may even be the mouse in your shed or garage! Finally, wood mice are also sometimes known as long-tailed field mice (contrasting with the short-tailed field mouse or field vole) as they are also found in fields. They are incredibly adaptable so also can be found in small populations in crops, heather and bracken.
Numbers
The current estimate for the number of wood mice in the UK is 39,600,000 (95% CI: 20,400,00 - 64,300,000) from the Mammal Society Review of the Population and Conservation Status of British Mammals. Their population appears to be stable in the UK. They can fluctuate rapidly in number as they can reproduce rapidly, but breeding is inhibited at high densities, acting as a population control.
Distribution
Wood mice are found across Europe from Spain to Ukraine, and into southern Scandinavia. In the south they are found along the coast of the Mediterranean to Greece and at the very top of north Africa. They are also very prevalent on Islands, including Iceland, Sicily and Crete, as well as most small islands in the UK. They are prevalent in all of Great Britain and Ireland, except the highlands.
Diet
Wood mice are very opportunistic, and so will eat almost anything they can including: nuts, insects, fruit, fungi and flowers. They will also consume crops such as sugar beet when they can. They tend to choose sugary foods earlier in their nights foraging, to provide energy for movement.
Size
Adult wood mice have a head-body length of between 8.1 - 10.3cm and a tail length between 7.1 - 95cm. They can weight from 13g to 27g. However some island population are much bigger, due to the phenomenon of island gigantism, and northern individuals are also larger.
Life span
Only around a year.
Breeding
An adult wood mouse in hand.
Wood mice can breed at anytime from March until October, and females can have up to 6 successive pregnancies in a season. They are promiscuous, so each litter will likely have multiple fathers. Litter size is usually 4-7 but can be up to 11, and weaning occurs after about 18 days.
Survey techniques
Most surveys for wood mice use live trapping, but there are a few signs to keep an eye out for in the wild. They create runs between burrow entrances, sometimes with food remains such as nuts with a messy hole and tooth marks along the outside, or such particles of other seeds. Their nests can be found in any cavity, such as nest boxes, and have a very loose structure of whatever leaves are near by.
Legislation in the UK
There is no legislation in the UK applicable to wood mice.
Leaping Mice
Wood mice have a characteristic bouncing movement a bit like kangaroos. This jump can be very high, as you can see from the video below! This movement distinguished wood mice from house mice or young rats which run along the ground. However, yellow-necked mice move in a similar way.
When wood mice are moving around they also use way-markers to navigate whilst foraging and then to find their way home. These markers are small objects, such as twigs, which the mice place in prominent positions along their route.
Communication
Wood mice communicate using visual, olfactory and auditory cues. They produce scent markers from a gland under their tail all the time they are moving, and also produce frequent calls whilst exploring. They also vocalise for mating, grooming and aggressive behaviours.
A group of wood mice playing around and foraging in front of a camera trap. Credit: George Hancock.