This species is active in the evening and at night (5), but during the breeding season it becomes more active during the day (5). Mountain hares tend to rest during the day in forms, scrapes or burrows in the snow or soil (4). Although typically a solitary species, occasionally groups of up to 70 individuals may gather in order to feed (5). The diet consists mainly of young heather, but grasses, rushes, sedges, bilberry and herbs are also eaten (5).
The breeding season occurs between February and August (5). During this time, several males may pursue a single female, who may 'box' them away if she is not ready to mate (4). Gestation takes around 50 days (4); between one and four litters are produced each year, consisting of one to five young, called leverets, although up to eight have been recorded (5). The leverets are born with fur, with their eyes open, and are left on their own for much of the time; the mother returns only to suckle them (4). Adult mortality is quite high (5), the main predators are foxes, birds of prey, stoats and cats (4), but adults are known to live to over nine years of age (5).