One Voice for Animals UK Guest Blog by Cumbria Badger Vaccination Project.
Today is National Badger Day (6th October), so it’s the perfect time to learn a bit more about our mysterious mustelids!
Because badgers primarily emerge from their underground homes at night, many people in the UK go full lifetimes without seeing – or even thinking – about them. This is a real shame, because badgers are such a gift to the world, and their ecology is absolutely fascinating.
We’ve come a long way in our understanding of badgers. There was a time where people believed the legs on one side of their bodies were longer than the others to help them move around on hillsides. I’m not sure how long it took for people to realise that this would only make sense if badgers only travelled in one direction… These days we’ve reached a point where we can put badger urine into a machine and work out what information other badgers can decode about the urinator when they sniff it, which is pretty impressive science! However, there’s still so much about badgers that we’ve yet to understand, and because their behaviour doesn’t align with that of most social mammals, they really are unique among all species.
With all that being said, here’s a bit more about them!
Badger Clanilies
Badgers are mustelids, which means they’re part of a diverse family group including weasels, otters and wolverines. However, they’re unique among mustelids in that they live in extended social groups. These groups are called clans, and in the UK, they typically comprise 4-8 members. The social structure of a clan is a bit less complex than that of most social carnivores, although there tends to be a top female who is responsible for the breeding, and a top male who likes to believe he is responsible for most of the breeding. In reality, female badgers aren’t particularly faithful, and 50% of all cubs are fathered by males belonging to other clans.
Badgers strengthen their clanily ties by grooming and scent-marking each other, using secretions from a subcaudal gland. This makes sense because badgers primarily perceive the world through their excellent sense of smell. Each badger’s individual scent is unique to them, and so the combination of scents of individuals within a clan smeared all over each member create an individual clan scent. If a badger meets another individual with this scent, they know that they’re a friend.
Although badgers live in groups, in many ways, they don’t act cooperatively. For example, cubs aren’t raised by the whole clan, badgers tend to forage for food separately, and they don’t defend areas as an allied group. ** Compared to other group-living mammals, badgers are in the early stages of developing sociality.
Where do badgers live?
Badger clans occupy home ranges, which are areas in which members spend most of their time. Up until recently, these were thought of as ‘territories’; but because badgers don’t invest a lot of energy defending would-be “boundaries”, and because there’s so much to-ing and fro-ing of badgers between adjacent ranges, we’re slowly moving away from that term.
Within its home range, a badger will have one or more setts. These are badgers’ underground homes, dug to sleep in, socialise, have their cubs, and shelter from bad weather. They’re networks of chambers and tunnels which combined can add up to 300 metres long, which is pretty impressive! They’re commonly found on hillsides in woodland near pasture or arable land, but you can find them just about anywhere. In the UK, lots of badgers build their setts in hedgerows, and in general, they do seem to like building entrances under sturdy objects such as rocks, walls, tree roots, and buildings. Setts can become persistent features of the landscape, with one being recorded in the Domesday book, and badgers tend to become attached to specific locations. This means that if a sett is covered up or built over, it’s likely that badgers will go in and re-excavate it. There was one incident where badgers re-excavated a sett underneath a new airbase and continued to live in it despite the sound disturbance! There are other stories of badgers re-excavating setts underneath churches, with congregations having to listen to sounds of scratching and badgers communicating while sermons were being held.
Speaking of badger chat, badgers have a whole range of somewhat unexpected vocalisations. This includes deep, warbling warning churrs and high-pitched playful squeaking known as ‘chittering’. When surprised, badgers can snort and bark, and when threatened, they can make a noise that almost sounds like clucking.
What do badgers eat?
In the UK, badgers are described as ‘specialist omnivores’ – ‘specialist’ because they’re skilled worm hunters, but omnivores because as the seasons change and the availability of different resources change, they’ll pretty much eat anything. This includes invertebrates and their larvae, roots and tubers, nuts and seeds, fruit, fungi, honey, amphibians, and small mammals/birds (usually in the form of carrion). There’s a myth perpetuated by the media that badgers are the cause of decline in numbers of hedgehogs and ground-nesting birds. While it's true that when food is scarce, opportunistic badgers may feed on these animals, such events are uncommon, and there’s plenty of footage of badgers and hedgehogs foraging side-by-side (they’re both fans of worms and other invertebrates).
Although their preferred food in the UK is worms, badgers in different areas of the world have different favourites depending on the availability of different food sources. In Italy, they like to exploit fruit and olives grown in farms. In Spain they like rabbits, and in Scandinavia they prefer carrion. Badgers’ extreme adaptability and determination means they’ve managed to populate pretty much the whole of Europe.
A Badger’s Lifecycle
Badgers can conceive any time of year, but they usually give birth in February/March time. This is made possible by a process called ‘delayed implantation’. At a very early stage of development (blastocyst level), cubs are suspended in their development before they implant into a badger’s womb, which tends to happen in winter. This is great for badgers because individuals can take advantage of any mating opportunity throughout the year rather than relying on coming across an attractive individual during a time-limited mating season. Individual foetuses can be conceived separately, which means siblings can have different fathers. Badgers are one of the only species that have mastered this incredibly useful trick.
After a further two months underground, cubs emerge in April/May time. Lots of cubs die pre-emergence due to cub-hood disease, so those that make it are usually pretty strong and prepared to take on the world. Growing up has to happen fast because summer and autumn are spent putting on as much body fat as possible to prepare them for the winter. Badgers don’t hibernate, but they do enter shorter periods of ‘torpor’ in cold conditions, which they regularly wake up from to check whether conditions have changed.
As with most animals, the primary goal for a badger is to reproduce as much as possible, although many females don’t get the chance. Badger females aren’t fans of monogamy, so lots of males do end up fathering cubs, even if they never make it to the status of top male.
The maximum life expectancy of a badger is about 14, however the average lifespan is 5-8 years. There are a few common causes of death among badgers. Old age, disease, poor weather conditions and injury (sometimes from fighting) are among them. Up until recently, now-extinct predators such as bears and wolves also posed a threat to a badger’s life. Unfortunately, natural predation has now been replaced by human persecution.
A bit about us: Cumbria Badger Vaccination Project
This post was written on behalf of Cumbria Badger Vaccination Project – a growing team working to vaccinate Cumbrian badgers from bTB as an effective alternative to the cull.
After a few years of surveying the beautiful reserve of RSPB Haweswater, we’re currently in our second year of vaccination. Our increasing number of volunteers has allowed us to expand the number of sites we operate in, which is fantastic for badgers, farmers and cattle alike.
If you’re in the area and would like to get involved, we’d love to hear from you. No prior experience is required, and your level of time commitment is completely up to you. If you’re interested, contact us via our Facebook page (Cumbrian Badger Vaccination Project), our Instagram (@cumbria_bvp) or by email (cumbriabvp@gmail.com).
This blog post was written by Eleanor Avon on behalf of Cumbria Badger Vaccination Project.
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