In spring males extend their range to seek mates. Probably only one litter, of 4-6 young are born per season. Young are weaned at 3-4 weeks and can kill efficiently at 8 weeks. Family groups split up at 9-12 weeks. Only one in 80-90 weasels survives to over 2 years old.
Weasels do kill some gamebird chicks, but probably very few.
Weasels have no legal protection in Britain. In bad rodent years many weasels starve and few of the survivors breed. Local populations often experience extinctions. However, weasels are extremely good at recolonising abandoned areas when conditions improve. Stoats are larger and have longer tails which end in a black tip.