Harvest mice are the smallest British rodent. They are the only Old World mammals to have truly prehensile tails.
Up to 18 months.
Head and body length: 5-8cm, Weight: 5-11g.
They have a blunt muzzle and small hairy ears. The tip of the tail is prehensile (capable of gripping) and is used to assist climbing. The fur is yellow/brown, with a white underside.
They range across Europe (although are absent from most of Scandinavia) E. Russia, Korea, S. China and N. Korea. In Britain, they are found from Yorkshire southwards and parts of Wales.
Harvest mice inhabit hedgerows and reedbeds, and other areas of tall, dense vegetation.
They feed mainly on seeds, fruits and bulbs, but a tiny proportion of their diet is made up of insects, particularly in the summer, as well as roots, moss and fungi. Some food is cached underground for the winter.
Harvest mice are active day and night, although most activity occurs at dusk. They do not hibernate, but spend most of their time underground in the winter.
Breeding nests are built in stems high above the ground. The spherical nests are made from woven grass and are about 10cm in diameter. Non-breeding nests are smaller (5cm in diameter) and may be built closer to the ground or in buildings.
After a gestation period of 17-19 days, the female gives birth to 1-7 young. They produce up to three litters a year. The breeding season ranges from May to October. The female abandons the young after 15-16 days, but the young may still use the nest for a further few days.
Harvest mice are categorised as Lower Risk by the IUCN Red List. Modern farming methods have caused a reduction in hedgerows, and combine harvesters leave harvest mice in grain fields with little chance of escape.