Where Are All The Hedgehogs?

Hedgehog numbers are falling. We can't let them disappear from the UK, but at present there's no dedicated way of monitoring hedgehogs. So the People's Trust for Endangered Species are creating a National Hedgehog Monitoring Programme this year and they want to know if you can help.

What they currently know about hedgehog populations comes from existing wildlife surveys, but none of these focus on hedgehogs, so there are gaps in knowledge. They know where hedgehogs are still present, as seen on the Big Hedgehog Map, but they don’t know in which areas hedgehogs are so scarce that it threatens their future survival. In other words, the People's Trust for Endangered Species need to understand hedgehog abundance. They also don’t know enough about populations in rural areas and how their numbers vary across different regions and habitats.

With colleagues, experts, and many, many volunteers they will survey a network of sites across the country, in a range of habitats, from April to October. At each site, 30 cameras will be in situ for 30 days, capturing images of any animals that cross their paths. An immediate challenge will be the sheer volume of images captured, so AI technology will assist the volunteers in spotting the hedgehogs amongst other animals and humans.

Once all the hedgehogs are identified, the data will be analysed, using pioneering technology. A key advance means the National Hedgehog Monitoring Programme will be able to convert 2D images into 3D maps. Using the precise positions of hogs and the speed they move across the camera, plus the size of the camera detection zone, they can establish densities of hedgehogs across all sorts of habitats. This simply wasn’t possible before. It’s a big advance, being able to calculate numbers of hedgehogs, not just that they’re present or absent. This 3D mapping is crucial and a really important step.

Then a national picture can be built over time. The People's Trust for Endangered Species has plenty of experience with national monitoring programmes. The oldest scheme, monitoring dormice, has over 25 years of valuable data. More recently in 2014, a water vole monitoring programme was set up as so little was known about where they remained. The data from both tells where endangered mammals need more help and where conservation work is working well. It's hedgehog's turn for national monitoring now!

The British Hedgehog Preservation Society and People’s Trust for Endangered Species, who together run nationwide campaign Hedgehog Street, are urging people to also connect as many gardens in their area as possible. This will allow local hedgehogs to roam between them in search of food, mates and nesting materials – a small action vital for the species’ long-term survival.


For more information click here