It may only be March, but the hedgehogs are already out and about in my garden. So I thought it was time to dust off the mammal footprint tunnel again. These are simple plastic tunnels that contain some tempting food, inkpads and paper, so when a mammal comes to investigate the food, they leave inky footprints behind. Here’s how to set one up.
What you need:
- A plastic footprint tunnel, big enough for your target animal to fit through
- A tracking plate (a simple sheet of stiff plastic that you put the bait, ink and paper on, and insert in the tunnel)
- Something tasty (see below for some ideas)
- Wide masking tape
- Black poster paint powder
- Vegetable oil
- Two sheets of A4 paper
- 8 paper clips
- Tent pegs to keep the tunnel in place
- Footprint guide
Assemble your tunnel
If you use a flatpack tunnel of the design recommended by the Mammal Society, all you need to do is fold it out, and insert the tabs into the slot – easy.
Get your tracking plate ready
This involves several stages:
- Paper clip a sheet of A4 paper at each end of the tracking plate.
- Put two strips of masking tape across the tracking plate, each the distance of just over the length of an A4 sheet of paper from one of the ends of the tracking plate
- Mix one part black poster paint powder with two parts vegetable oil (I used sunflower oil), so if forms a smooth black ink. This is safe for mammals to lick off their paws, and stays damp for several nights. 1 teaspoon of powder and 2 of oil will be enough for your tunnel for several nights. If you make up more than that, keep the excess in a sealed jar until you need it
- Apply a layer of ‘ink’ to the two strips of masking tape
Site your tunnel
Now pick a good spot to place your tunnel. Next to / under hedges is a good spot (hedgehogs live up to their names), or along a fence or shed, or on the edge of grassland or woodland. I put mine next to a small garden hedge.
Make sure the tunnel is flat on the ground, and use the tent pegs to keep it in place (you’ll need to pierce a hole in the floor of the tunnel for this, but that’s easily done with a pen knife).
Pick your bait
Previously I’ve had good results with dried mealworms that have been soaked in water to rehydrate them. This time I’ve tried experimenting with berry suet pellets (that are sold as bird food), more mealworms, and dried cat food soaked in water. The hedgehogs have hoovered up everything I’ve put out, so I can’t make any recommendations as to which they prefer, but any of those seem to work. You could also try peanuts (of the sort sold as bird food) (I have a nut allergy, so steer clear of these), bits of hotdog sausage, seeds or bits of fruit.
Last year when I was using the tunnel I put the bait directly onto the tracking plate (in the middle, between the two ink pads). The disadvantage of this is that bits of food end up in the ink, which is messy. So this year I’ve taken to putting it in a little ramekin (of the sort posh puddings come in), which has kept things cleaner. The ramekin does tend to get dragged about in the tunnel, but at least I don’t have to pick bits of mealworm from my ink pads.
Insert your tracking plate into the tunnel
Insert your tracking plate (complete with bait) into the tunnel, and you’re all set for the night.
The next morning
Check your tunnel by removing the tracking plate. Hopefully anything that’s been eating your bait will have left inky pawprints on the paper. All you need to do then is work out what sort of pawprints they are. This can be tricky with some species, but hedgehog prints are fairly distinctive.
If you do get any mammal pawprints, please do report these data to the National Mammal Atlas Project or use the Mammal Tracker smartphone app.
Don’t be too disheartened if you don’t get hedgehog prints after the first night – they tend to travel about quite a lot each night, and may not visit a particular garden every night.
The next evening
Replace the paper with fresh sheets, put more bait out, and check that there is still plenty of ink (topping up if needed).
What I’ve found
Previously I have had hedgehogs, mice and slugs visiting the tunnel. So far this spring the tunnel has only be used by hedgehogs. Here’s a sample of prints I’ve had this week.
Where to get hold of a mammal tunnel
Wildcare sell an easy-to-use mammal tunnel kit that contains the tunnel, tracking plate, a small amount of black poster paint powder, some pegs and a pawprint guide.
You’ll need to provide your own vegetable oil, paper, paper clips, bait and masking tape.
Alternatively, it would be fairly easy to make your own tunnel, if you happen to have suitable materials lying around.
Wild South 
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