Badgers

I have watched wild badgers for many years, and was lucky enough to encounter one up close when I worked on a project in Dublin. A flood defence wall was being built along a river, and a badger sett was along the river too. The new wall would cut through the sett, so the decision was made to build an artificial sett. We would trap the badgers, move them to the new sett and feed them for a month or two. We would then release them and allow them back to their old sett when the work was finished.

The badgers were very resistant to being trapped. Night after night we sat for hours, watching cats, foxes and everything else go into the traps. And then one night, Michael appeared. He was a young badger, with a bad gash on his head. He had clearly been in a fight with another badger – or with a car. He sat quietly in the badger trap until he saw us, and then, in total despair, he covered his eyes with his paws and made loud sobbing sounds. Honestly, he looked like a large, sad, furry toy.

When we moved him to the new sett area, I opened the cage. But like a kidnap victim with Stockholm syndrome, he refused to leave and huddled in the corner. How would we get him out of the cage? I took a stick and started gently pushing him out. He removed his paws, looked at me with a clear look of ‘please stop torturing me!’, then placed his paws back over his face and resumed sobbing. He was like a child who is so upset that they can’t catch their breath. Poor Michael.

We crept away and waited, and finally he shot out of the cage, and down to the new sett. It was several days before he was brave enough to come out for food.

Badger setts

One hole in the ground looks much like another hole in the ground when you are trying to identify mammal underground homes, but if you can fit a football inside the hole, you probably have a badger sett. If you do find a sett, keep it a secret. Badgers have been persecuted for many years by badger baiters, and traps and snares are still set today by these cruel people.

There are several different types of sett, and they can be enormous. The main sett is like the ancestral home. It has been passed down through the generations, and badgers are extremely attached to it. They often bring in pieces of plastic bag to line it with, making it waterproof and giving it a strange interior design aesthetic. My husband found one that was lined with hundreds of Coca-Cola bottles. Main setts are big, with lots of entrances, and are used most of the time. Many setts have indoor toilet areas.

The annex sett is like the granny flat, with a smaller number of entrances, generally used when badgers want to have a quick night away from the relatives. The outlier sett has just one entrance and is further away – a bit like a holiday cottage, when they plan to stay out all night and they’re far from home. Of course, these sett descriptions can intermingle. Just like ourselves, badgers move around and change the design of their homes.

As badgers extend their setts, they drag out a lot of soil. They use their hind legs to kick the soil out, moving backwards in their tunnels. The soil that is dumped at the entrance is called a spoil heap. So, in addition to the football-sized hole, you may find some mounds of soil – and also some dried grass and bedding.

Badgers are exceptionally clean animals and, like myself, they often drag out their bedding to air it. I hang my duvet on the line, but they spread their bed around in the sunshine. This cleans it and gets rid of parasites. The same process gets rid of dust mites in my duvet. Then they inspect their bedding, judging whether it has to be thrown out or can be reused, before dragging it back into their chamber.

Tunnels are usually semi-circular, with corridors leading off them at sharp angles. The tunnels lead to chambers, which are a squashed oval shape, about half a metre high and wide. The sett must be warm enough to protect the badger (some research shows that the temperature inside the sett is around 11°C) while allowing enough oxygen through so the animal can breathe. The chambers must also fit bedding, plus another badger sometimes. It must all be a little squashed.

Sometimes tunnels where a badger has died are closed off, providing an underground, in-house burial chamber. Later on, when only a skeleton remains, spring cleaning is done and the skeleton is tossed out with the soil. If you ever find a skull, and are wondering what it is, lift it up (wear gloves!). If the jaw remains attached, it is a badger skull. Their lower jaws are attached by bone. You are probably moving your jaw around right now, as I am, wondering how our jaws are attached. Unlike those of badgers, our lower jaws are only attached by muscle. Without this muscle, our lower jaw would fall off. Now that’s something to chew on!

Two captive badgers were recorded building their own heating system. They carried straw and hay to a chamber within their sett and allowed it to ferment. It reached 38°C, and the badgers would move closer to it when they were cold. They did this several years in a row.

Who does the housework in the sett? Not surprisingly, it seems that the parents do most of the work, digging and carrying bedding around. Older males and females spend a lot of time keeping their home clean, while the sett is used by the whole group. It’s just like Christmas in most households.

We built an artificial sett at home. There are many designs on the internet for homemade sett design, so it might be worth giving this a try. Four years later, badgers still have not moved in – but they have started to mark the sett with latrines (little toilets) outside the entrance. Perhaps they are trying to tell me what they think of my sett! After all, if you had a perfectly good ancestral home, why would you move into a home built by another species? If badgers built a home for me, I might appreciate the toilet areas and heating systems. But I wouldn’t enjoy the tiny rooms and long corridors, and my ancestors being sealed into the walls. Meanwhile, my badgers visit our sett regularly. They check out my grand design and have some peanuts and a poo. As humans, we are probably getting something wrong when we build artificial setts.

Badgers and bovine TB

Badgers suffer from tuberculosis, or TB. The million-dollar question is whether they can transmit TB to cattle. I believe it is very unlikely that a cow will catch TB from a badger. And here is the science behind my opinion:

TB in cattle is usually found in their lungs. For a badger to infect a cow, it would have to come within 1.5 metres of the cow, and ideally be breathing at it. Sadly, we all now understand about social distancing and aerosol droplet dispersal. And lots of interesting science has taken place in Ireland, looking at badgers and cattle, and their social distances.

A project led by National Parks and Wildlife Service (NPWS) Divisional Ecologist Enda Mullen spent three years tracking badgers in the Wicklow countryside. Forty badgers, from 12 social groups, had radio collars placed around their necks. Then enthusiastic NPWS staff and volunteers from Trinity College Dublin plotted 12,500 movements of the badgers as they roamed the countryside.

How would the badgers meet the cattle? Might a badger be lured into a farmyard by some spilled grain, coming into contact with livestock housed in sheds? This study proved otherwise. The badgers tended to avoid farmyards – and particularly farmyards with cattle. If they visited farmyards at all, they tended to visit equestrian farmyards and disused farmyards. But most badgers kept away even from these. A single individual badger (which the researchers christened ‘Violet’) seemed to like a trip to the horses, and went to visit a stable several times, but most other badgers kept far away from all livestock, and were even scared of visiting disused farmyards.

A second study, undertaken by Declan O’Mahoney in Northern Ireland, confirmed that badgers avoid cattle. Declan works with the Agri-Food and Biosciences Institute in Belfast, and his approach was slightly different. He placed proximity collars on 58 cattle and 11 badgers in a bovine TB (bTB) hotspot in Northern Ireland. If the badgers and cattle came within 2 metres of each other (close enough to share a breath), the collars would emit a pulse. This would be plotted via GPS. In addition, motion-sensor cameras were placed all over the farmyards to video anything that moved.

The results were amazing. There were over 350,000 interactions between cattle and cattle. There were 11,774 interactions between badger and badger. Clearly, you hang out with your own species. And there were no interactions between cattle and badgers. Zero!

So, is TB being transmitted by badgers? And if so, how? The researchers looked at water troughs. But badgers and cattle did not use water troughs concurrently. In fact, badgers rarely used water troughs at all. So, the researchers turned their attention to the farmyards. In a mammoth undertaking, they recorded 500,000 hours of video at farmyards and analysed the results. That must have been a really tedious job! The visiting animals recorded most were feral cats, some of which were in poor condition. Farm cats play an important role in rodent...