occupies any part of the forest. It is usually found in mature deciduous woodland is also found in scrubby areas, hedgerows, orchards and plantations. It favours areas where there are large, nut-bearing trees such as the oak and the hazel. It is also found in parks and gardens and beside alder-fringed streams. Behaviour The yellow-necked mouse is active all year round and does not hibernate. Sometimes several mice will huddle together during the winter to preserve heat. It is an excellent climber and scrambles around in trees and bushes. It lives in crevices, burrows at the base of trees, holes in tree trunks, hollow logs and bird nesting boxes and sometimes enters buildings. The burrows are often extensive with many entrances and complex layouts. It makes extensive stores of food such as acorns and beechmast in storage chambers and uses other chambers for nesting, bringing in dry plant material for this purpose. There are often mounds of earth outside the entrances to the burrow. It also makes larders of food in holes in trees away from the burrow. The shade is very dense under a beech tree in summer and it has been found that beech nuts hidden in caches by the yellow-necked mouse, and not subsequently eaten, can later germinate and help with dispersal of the parent tree. The yellow-necked mouse is nocturnal. It is active on the ground and in the tree canopy and has a home range rather smaller than half a hectare. Besides nuts, it feeds on buds, shoots, fruit, seedling plants and sometimes small invertebrates. Breeding takes place at any time between February and October with successive pregnancies occurring at short intervals. The gestation period is about twenty six days and females can remate while still feeding the previous litter. A litter of young is born in a nesting chamber lined with dry plant material and consists of two to eleven (usually five) altricial young born naked, blind and helpless. The eyes of the young open after about a fortnight and their yellow collars are visible by then as grey patches. They are weaned at about eighteen days old. If they are born early in the year, they may start breeding in the same year, but late-born young become sexually mature in the following spring. The yellow-necked mouse is preyed on by owls, foxes, weasels and other predators. It can leap to evade attackers and