Mammal Tracking in Winter
Written by Elen Sentier, 2022
On bright, crisp winter days sunshine I love to go tracking. My favourite mammals to track are the mustelids: badgers, otters, pine martens, polecats, stoats, mink and weasels.
The badger is our largest UK mustelid, about 75-100cm long, their tail is just 15cm, they weigh in at 8-12kg, and can live for 5-8 years. They’re powerfully built, stocky animals with black-white-brown-grey fur, a smallish head with a good snout, small black eyes, a short tail and big paws with five toes with long claws. They’re very social and sleep together during the day in their sett. The setts are extensive systems of underground passages with multiple chambers and entrances – hence the need for those big paws. Setts are passed down through families, and are continuously improved if left alone, so can be a hundred years old or more! Badgers dig latrines, so their scat is fairly obvious to find a bit away from the sett itself. Their droppings may be firm sausage shapes, or softer, slimier and darker if they’ve eaten lots of worms, and smell sweet and musky.
Next is the Otter. They’re typically they’re 60-80cm long and half of that is the big swimming paddle tail, weigh in at 6-8kg and can live for 5-10 years. Being semi-aquatic, their toes are webbed but that may not show in the tracks, look out for a tail drag line behind the prints. Look for otter prints in the muddy banks of streams and rivers, and you can find their dung there too – it’s called spraint – and they leave their spraints on rocks or logs close to water. The spraints are greenish/black/grey in colour and sweet smelling like jasmine tea or laurel flowers. They eat mostly fish and crustaceans, small mammals. They have 5 clawed toes.
Now we have my favourite mustelid, the Pine Marten. They’re chestnut-brown in colour, darker in winter, with a pale yellow 'bib' on their chin and throat. The bib is unique to each marten making for easy identification on camera traps. They’re slim, typically 46-54cm long, with a long, bushy tail of 18-27cm and weigh in at 0.9-2.2kg and can live up to 8 years. They like woodland habitats, are super climbers and live in tree holes, old squirrel dreys, or even old bird nests and eat small rodents, birds, eggs, insects and fruit. They also attack and eat grey squirrels so can be a good countermeasure that will keep them under control. Again, they have 5 clawed toes.
Next is the Polecat, a cousin to our domesticated ferrets. They’re 32-45cm long with 12-19cm tails and weigh in at 0.5-1.9kg and live for about 5 years. Their coats have blackish guard hairs and yellow underfur on the body so they have a black-and-tan appearance, pale muzzle, ear tips and eyebrows, with a broad dark band around the eyes (bandit face), darker legs and belly, and a short fluffy tail. Polecats set up home in lowland wooded habitats, marshes, along riverbanks and even in farm buildings or dry stone walls. They prey on rabbits, following the rabbit down into the burrow. They have one litter of five to ten young a year in early summer. Polecats have five toes and long claws but the pattern and spacing is different to the otter.
Now we come to the Stoat, also known as the ermine because it gets a white coat with a black tail-tip in a snowy winter. Stoats are slim-bodied, with a short, black-tipped tail. Chestnut brown on top with a sharp division separating the underparts. Their coat turns pure white (except for black tip to tail) in cold northern regions. Stoats are about 25cm long with their tail about 7-8cm, and they weigh in at 140 - 445g. Females may be up to 50% smaller than males. Both genders live for an average of 1-2 years but can live up to 7 years. They live in woods, farmland, uplands, moorlands, marshes, sand dunes and hedgerows and mostly eat rabbits and other small mammals, but also birds, eggs, earthworms, large insects and carrion. Like other mustelids, they have 5 clawed toes.
Now we come to the smallest of the mustelids, the Weasel. They’re long and slim with a short furry tail, reddish-brown upperparts divided from the white underparts by a wavy flank line. Males are about 21.5cm - 28.5cm, females smaller, and 4 - 6cm to the shoulder. Males weigh about 115g and females up to 59g. They live for 1 - 2 years in the wild and up to 10 years in captivity. They live in woodland, hedgerows, farmland, moorland and mountains. The weasel is a fierce hunter and Britain's smallest carnivore, they eat mainly mice and voles but also rats, moles, small birds, birds' eggs, and even rabbits much bigger than themselves. Like its fellow mustelids, it has five clawed toes but again the pattern is distinctive.
Enjoy searching for mustelids this winter – you’ll learn a lot from these fascinating animals as you understand where and how they live.
Please report what you find, and where, to the Mammal Society. This really helps us map out where species live and so protect them and their habitat for the future! Learn more about reporting mammals here.
To learn more about all the mammals in this article visit our Mammal Hub.