Harvest Mouse Micromys minutus
The elusive, amber coloured harvest mouse is smaller than other British mice and tends to live in grassy habitats. The furless prehensile tail acts like a fifth limb enabling it to climb plant stems and their broad feet are perfect for extra balance. This tiny creature is fairly difficult to spot in the wild.
Conservation status in Norfolk
The conservation status of the harvest mouse is currently unknown. More information is needed on the distribution of harvest mice populations in Norfolk. Undoubtedly they have become rarer in cereal fields because of increased mechanisation and especially the use of combine harvesters. However, on the plus side, harvest mice are known to occur in a much wider range of habitats than previously thought.
How to help
Avoid strimming or cutting areas where harvest mice nests have been found until autumn. If you have to cut in the May to August period, leave some refuge areas of tall vegetation, and check carefully for nests before you cut
Paul Laurie
Information on the Harvest Mouse
How to recognise
Harvest mice have distinctive orangey-brown upperparts and pure white under parts. They are the only British animal to possess a prehensile tail which can be twisted around plant stems to act as a ‘fifth’ limb to help them climb. They are smaller than other British mice and, unlike wood and house mice, have a blunt, vole-like muzzle rather than a pointed one.
Where to see
Probably widespread in suitable tussocky grassland habitats across Norfolk. Recent research has shown that reed beds are also an important habitat for this species with good numbers occurring at sites such as NWT Hickling Broad. Any area of rough grassland with tussock-forming species, such as cocksfoot, may support harvest mice.
When to see
This species is elusive and difficult to spot. Harvest mice are active both by day and by night, but they are still a notoriously difficult animal to see in the wild. Look out for cricket-ball sized summer nests of woven grass and stems built above ground in dense vegetation. These nests are so well constructed that they survive through to autumn and early winter – good times to look for the now empty nests which are easier to spot once the leaves have fallen.
Did you know?
The harvest mouse is Europe’s smallest rodent, weighing between 5-10 grams and measuring 50-70mm.
Related questions
What does a harvest mouses nest look like?
The harvest mouse is our smallest rodent, and is the only mouse to build a nest of woven grass above ground.
Harvest mice nests are constructed on stalks of grasses such as cocksfoot (Dactylis glomerata), common reed or in cereal fields. The nests are found at least 30 cm above ground, and may be higher in tall reeds. They can be as small as 5 cm in diameter for non-breeding nests, and up to 10 cm in diameter for breeding nests.
The outer framework of the nest is constructed by weaving a large number of shredded grass leaves. The nest is then lined by pulling further grasses through the wall until it is densely woven without leaving an obvious entrance. Nests are more conspicuous in winter when the surrounding vegetation has died down.