The Yellow-necked Mouse (Apodemus flavicollis), is a close relative of the wood mouse, with which it was long confused, only being recognized as a separate species in 1894. It is found mostly in mountainous areas of southern Europe, but extends north into parts of Scandinavia and Britain.
It differs from the wood mouse in that it has a band of yellow fur around the neck and in having slightly larger ears and being slightly larger overall. It is about 4 inches long. It can climb trees and sometimes will over-winter in houses.
Photograph by James Lindsey