Inspired by the lightweight portable Mammal Footprint Tunnels available from the Mammal Society I thought I would have a go at making my own, more permanent version for the garden. I of course wanted to give it the Wildlife Gadgetman twist so I decided to incorporate a small nightvision camera too so we can see the tunnel in action and watch the small mammals leaving tracks.
The first stage is to make the tunnel itself. The two crucial design points at this stage are a) Ensure the inside of the tunnel is easily accessible making it a doddle to change the paper inside and re-ink the ink strips whenever needed, and b) Ensure the internal dimensions are the right size to allow for two sheets of A4 paper (210 x 297mm), two ink strips (210 x 100mm) and a recessed area to hold the food (approx 170 x 40mm – Depth will depend on the thickness of material used). Allowing for small gaps between each of the internal elements I decided to make the internal dimensions of the tunnel 215mm wide x 1000mm long x 200mm high.
The next thing to consider is the size of the openings either end of the tunnel. Too big and you’ll end up with lots of visits from local cats, too small and you could potentially exclude larger hedgehogs. I originally made the openings 80mm high and found that this did indeed exclude the local cats (see video clip below) but it also prevented one of the larger hedgehogs in the garden from getting inside too (see video clip below). I therefore increased the openings to 100mm and was pleased to find that this was sufficient to allow access to all hedgehogs visiting.
To hold the paper in position I used some elasticated cord. I simply drilled four holes fractionally wider apart than the paper is long, threaded the elasticated cord through each pair of holes and secured each end under tension (see photo above). The paper slips neatly under the cords and is held firmly in position.
To enable me to keep the ink/paint area as tidy as possible I decided to place a piece of plastic sheet either side of the food to put my inky paint mixture on. I used two thin strips of wood (fixed in the centre) to act as a grip for the plastic sheets (see photo above). This makes it easy to quickly replace the plastic if needed.
Creating the inky paint mixture
To create my inky paint mixture I used non-toxic black powder paint and a small amount of vegetable oil. Add just enough oil to the powder paint to give you a single cream consistency when mixed. The oil prevents the paint from drying out and will last several days.
Completing the camera installation
The final stage is just to complete the installation of the camera. I used a 700TVL dome camera with 36 infrared LEDs. The camera has a 2.8-12mm manual zoom and focus control so I can adjust the field of view and focus to highlight the centre of the tunnel. All the camera connections were placed inside a weatherproof box on the side of the tunnel and the cable was routed back to my office and connected to my I-Catcher motion detection software.
Here’s the Mammal Footprint Tunnel in its final position in the garden. Everything is set up and ready for the first visitors.
Within hours of the tunnel being deployed it was attracting it’s first visitors! To date I’ve seen field mice, voles and hedgehogs inside along with the odd frog and an inquisitive Wren!
I’m thrilled with the success of the tunnel! Incorporating the camera adds a whole new dimension to the experience. It’s fascinating watching the visitors and intriguing to see how they react to the inky paint patches. To date I haven’t noticed ANY reaction to be honest. I expect they have stood in much worse!
Check out the photos and video clips below of the Mammal Footprint Tunnel in action.
The mammal footprint tunnel in action
The First Visitor!
Footprints After The First Night
Fantastic Hedgehog Prints!