Both animals belong to the mustelid family which in the UK also includes the much larger badger and otter as well as the elusive pine martin and polecat. They share several characteristics including a scent gland which produces a strong-smelling secretion used to announce presence and mark territories. There’s also a large introduced American mink population which isn’t native to the UK.
Stoats and weasels are the smallest of Britain’s mustelids and they are well distributed across our region, inhabiting farmland, nature reserves, parks and gardens where there is a ready source of food in the form of small mammals. Stoats will eat a range of food but have a preference for rabbits, so they are most common where rabbits are numerous. Weasels on the other hand will take a range of small mammals including mice and voles so can be spotted a little more widely.
If you’re lucky enough to spot one it will either be a flitting sight of a small one as it scurries across a road in the car headlights or as it scarpers into undergrowth. Very occasionally if you’re in the right place and sitting quietly they’ll be unaware of your presence and you might get a more lingering view.
At first glance stoats and weasels look similar but there are a few things to look for if you think you’ve seen one. Stoats are the larger of the two creatures, growing up to 25cm with a solid long body, whereas weasels are rarely bigger than 20cm but will look slender and sinuous. Stoats and weasels are both brown with a pale, white belly but the dividing line between the colours is straight on a stoat and irregular on a weasel. When moving, stoats have a bouncing gait as they progress through grassland compared to weasels which move fast and continuously lower to the ground. The most obvious difference to look out for is the black tail tip on a stoat which is generally visible and held vertically. The weasel has a shorter brown tail which it tends to hold close to the ground.
In some areas, stoats change their coats in winter to a white form which provides them with camouflage against a snowy backdrop. This ermine form was used to make the garments worn by nobility and royalty which feature white fur with black spots. The spots themselves are the tails of the stoats which remain black even in their winter coloration. In contrast to the weasels, white stoats where often represented in art to define purity. Young unmarried women, including Queen Elizabeth 1st, are often portrayed in paintings with an ermine stoat to signify this.
So, there are many associations in art and folklore with these small and elusive mammals, and if you do get a fleeting glimpse of either a stoat or a weasel be thankful that you’ve been given the honour.