The world’s smallest carnivore, the weasel is a voracious hunter. With long, slender bodies and short legs, weasels are surprisingly energetic and can eat a third of their body weight each day.
Although small, weasels don't hibernate or slow down in winter.
Weasel facts
Scientific name: Mustela nivalis
Family: Mustelids
Diet: Birds and smaller mammals, like rabbits and rodents
Predators: Foxes and birds of prey
Size: 17-22cm with a 3-5cm tail
Weight: 55-130g
Lifespan: 2 years
About weasels
Belonging to a group of animals known as mustelids, weasels are known for their long bodies and short legs. They don’t look dissimilar from their cousins – badgers and otters. Weasels are even more closely related to ferrets, polecats, and stoats, who are of the same genus (Mustela).
These bold predators generally hunt alone and can travel up to 2.5km in pursuit of food. However, they cannot store fat, so often store excess meals for later.
Weasels and our canals
You can find these elusive creatures in plenty of different habitats. Widespread throughout the UK, weasels make their homes in woodlands and grasslands and can be found near our canals, rivers, and reservoirs.
They prefer areas with dense vegetation to provide cover from predators and hunting grounds for prey – like bank voles. Take a look at the hedgerows and undergrowth along our canals for a chance to spot a weasel darting after its next meal.
Weasels have reddish-brown fur on their back with a white underside and throat. Their long, tube-like bodies end with a short tail. Although they look quite similar to the stoat, they are smaller and don’t have a black tip on their tail.
Aggressive predators they may be, but weasels are not much bigger than their prey. They’re typically around 20-27cm from head to tail. Females are smaller than males, but both are able to follow mice, voles, and other rodents into their own tunnels.
A weasel reddish-brown fur and a white underside, small black eyes, and long whiskers perches on the dead wood of a tree hollow.
What do weasels eat?
Weasels hunt night and day, in any season – even in snow. With a fast metabolism, they need to eat a lot to survive, usually consisting of field and bank voles and mice.
The weasel’s small size means it can follow the rodents into their underground burrows. However, it doesn’t stop them from pursuing larger prey, like rabbits. Weasels are also excellent climbers, often feasting on birds and raiding their nests for eggs.
How do weasels breed?
Weasels are solitary animals, only gathering to mate between April and August. The female gives birth to around four to six young, known as kits, in a litter. She has between one and two litters a year. Unlike stoats, weasels cannot delay implantation.
To raise their young, weasels take over a den from rodent prey. Kits are weaned after three or four weeks. The first litter grows quickly and can hunt and kill prey at eight weeks old.
Where do weasels live?
Widespread in England and Wales, weasels are common in a number of different habitats.
They can survive anywhere there is prey to eat and cover to shelter in. Weasels rarely spend long in the open, making them hard to spot, preferring to hunt in long grass and dense vegetation.
Small in size, speedy, and their preference for staying under shelter means weasels aren’t often seen.
Next time you’re on a woodland walk or along one of our towpaths, keep your eyes peeled and watch the undergrowth to see if a weasel darts across your path on the hunt for food.
What’s the difference between a weasel and a stoat?
Stoats (pictured left) and weasels (pictured right) are closely related, but small differences distinguish the two. Stoats are larger with longer tails that end in a black tip, whereas the weasel’s tail is completely brown.
However, as most glimpses of Mustela are fleeting, you might not get a chance to examine its fur and judge its size. The best way to differentiate stoats and weasels on the move is to compare their gait. Stoats tend to bound along, while weasels run quicker and closer to the ground.
Threats to weasels
While weasels are widespread, the loss of habitat across the UK remains a threat to their survival. Weasels rely on hedgerows and areas with dense vegetation to hunt. Our canals provide crucial habitats for weasels and other wildlife.
