For day six of our 12 Days of Winter Wildlife we are celebrating the world of winter mammals, particularly focusing on those that might be out and about during the colder months of the year. One mammal that is doing pretty well in towns and cities as well as the countryside in the UK is the red fox. We are lucky enough to have a fox skull in the Museum’s handling collection, so you can find out more about its adaptations here:
Winter Wildlife: Mammals
Dr Roz Wade, Learning Officer at the Museum of Zoology, writes:
There are around 90 species of mammal living in the UK today. Here are just a few: three that are active in the winter months, and three that spend this time in hibernation:
Red Fox, Vulpes vulpes:

With its orange fur, bushy tail and pointed ears, the red fox is unmistakable. A member of the dog family, male red foxes will bark, but female red foxes make more of a screeching sound. Foxes are very adaptable animals, and are at home in towns and cities as well as in the countryside. They have learnt to feed from our scraps, found in dustbins and compost heaps, as well as hunting and scavenging for food. Foxes are described as crepuscular – they are most active at dawn and dusk. But you can see foxes out and about during the day, particularly in urban areas where they have become more used to the presence of people. Find out more about foxes on the Mammal Society website.
Badger, Meles meles:

Badgers are sturdy mammals with powerful jaws and a characteristic black and white striped head. They live in complex networks of tunnels and chambers underground called setts. A sett is home to several badgers – usually around six adults but sometimes there can be more than 20 in a family group. Badgers are found across the UK, and while territories are usually in woodlands and other countryside, they can live in parks in cities too. Badgers are nocturnal – coming out at night to feed. They are omnivores, and will feed on small mammals, eggs, and fruit, but most of their diet is made up of earthworms. They can eat hundreds in a single night. Badgers don’t hibernate, but they are not as active during the winter, often spending nights as well as the daytime underground. Find out more about the badger’s year with Discover Wildlife. And discover some of the amazing adaptations in badger skulls in our Exploring Skulls video
Grey Squirrel, Sciurus carolinensis:

If you’re going to spot a mammal in the UK, it is likely to be this one. The grey squirrel is not native to the UK, having been introduced here from America in the 19th century. Since then, this species has been pretty successful, out-competing our native red squirrels that are now found in only a few places in Britain. But have you ever seen a black squirrel?
There are estimated to be around 25,000 black squirrels in Britain, a population centred around Cambridgeshire, Bedfordshire and Hertfordshire. Black squirrels are actually grey squirrels with a mutation that stops a genetic ‘switch’ to cut off the production of black pigment when the hairs are growing from working, creating black hairs instead of the usual stripes of white, black and orange. You can find out more about black squirrels and the research of Dr Helen McRobie of Anglia Ruskin University into these fascinating animals here.

Hibernating Mammals
There are some mammals you are unlikely to see over the winter months. Instead of being out and about finding food, these animals hibernate. They drop their body temperature, slow their metabolism, and survive off the reserves of fat they develop during the autumn.

Perhaps the best known hibernators are hedgehogs. At this time of year, they will have built a nest of dry leaves and other materials in a safe spot, such as under hedges, in abandoned rabbit burrows or even beneath the garden shed. Over winter, try not to disturb hibernating hedgehogs – if you have a hedgehog house, don’t open it, and don’t clear away piles of leaves or log piles. Find out how to be a Helpful Hedgehog Hero.
Another group of mammals to hibernate are bats. They will look out for holes and gaps in trees, caves, and sometimes the roof spaces or other nooks and crannies in buildings as places to roost over winter. They usually enter hibernation in November, and may not be fully active again until April or May.
The last of our hibernators are dormice. The name dormouse comes from the French dormir to sleep, and they hibernate from October to May in nests on the ground usually under hedgerows or on the forest floor. You can find out about the work taking place at Brampton Woods to conserve the hazel dormouse with this film by Ellie Bladon:
Meanwhile, at the coast… Dr Andrew Bladon writes:
I love making an annual pilgrimage to go and see the grey seals pupping at Horsey Gap in Norfolk. Grey seals are the UK’s largest carnivore, and around our coasts are many internationally important sites for the species.
Each year, in the middle of winter, pregnant females haul up on beaches around the coast to give birth. They feed their pups for a few days, in which time the pups grow rapidly on the rich, fatty milk. The males also come ashore at the same time, to mate with the females ready for the following year. Then the mothers head back to sea, leaving their pups to grow and moult on the beach for another few weeks before braving their first swim in the cold waters. When visiting the seals, it’s really important to keep a good distance, stay quiet, and keep dogs on leads, as the seals are easily disturbed. If a mother leaves her calf too early, it will not have enough food to survive.
Winter Games: Food Cache Memory Game
Squirrels don’t hibernate, but they are less active during the winter. To help them through the colder months, they hide food in different places to find when they need it. This behaviour is called caching. Squirrels are surprisingly good at remembering where they have hidden food. Create our caching memory game to see if you have a memory as good as a squirrel’s.
This activity is part of the Mill Road Winter Fair. Find more activities like this from across the University of Cambridge Museums here: Explore and Create
12 Days of Winter Wildlife Day 7: Winter Visitors

Visit the blog again tomorrow to discover the birds that escape the extreme cold further north by migrating to the UK for winter. Read winter visitors profiles and and listen to recordings of their calls by Dr Tony Fulford. Take a virtual tour of the winter visitors on display in the Museum of Zoology, and get inspired to make sweet treats and wrap them sustainably as winter gifts.
12 Days of Winter Wildlife catch up:

Catch up on Day 1 of our 12 Days of Winter Wildlife. Watch the livestreamed launch, including a virtual tour of the wildlife in the Botanic Garden, a Q&A with Rob Jaques of the British Trust for Ornithology, and sing along with the premiere of the 12 Days of Critters song. Read the top winter wildlife tips from staff and students at the Museum of Zoology. Download our Winter Wildlife spotter sheet, and create your very own hedgehog in a leaf pile.

Catch up on Day 2 of our 12 Days of Winter Wildlife: Garden Birds. Enjoy a wonderful film about attracting birds to your garden by Dr Andrew Bladon, listen to recordings of garden birds in winter by Dr Tony Fulford, and learn how to make seed cakes for birds with Lucy Williamson.

Catch up on Day 3 of our 12 Days of Winter Wildlife: Active Insects. In this post we explore the amazing world of moths that are active during the winter moths. Find out about moth-trapping with a film from moth expert Annette Shelford, discover winter moths and December moths with Research Assistant Matt Hayes, and make your own moth decoration out or recycled fabric with Museum Volunteer Natasha Lavers.

Catch up on Day 4 of our 12 Days of Winter Wildlife: Life Underground. Join Dr Ed Turner, Curator of Insects, as he gives his top tips for creating a compost heap, and shows you some of the amazing animals that live there.

Catch up on Day 5 of our 12 Days of Winter Wildlife: Hibernation. Find out about the insects that huddle away and stay dormant over winter with Matt Hayes, and create your own insect refuge for the garden with Sara Steele.
And remember to send your winter wildlife spots and creations to us by tagging us on social media or using #12DaysofWinterWildlife and you could feature in our online community gallery.

Find out more about British mammals with Wildlife From Your Window posts on:
Rodents
Squirrels
Otters
Become a Helpful Hedgehog Hero
Zoology Live Nighttime Wildlife
And with Our Changing Planet explore the conservation of British carnivores.
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