How Sherwood is helping to home in on hedgehog habitats

It’s that time of year when some of our wildlife is getting ready to hunker down for the cold months ahead.

Hibernation is the process of saving energy and slowing down the body’s functions at a time when natural food is scarce.

One of the mammals we most immediately think of when we hear the word ‘hibernation’ is the hedgehog.

A hibernating hedgehog, curled into a spiky ball tucked inside a cosy bed of leaves, is an almost quintessential image of British wildlife in winter.

But today, hedgehogs are facing challenges just as fundamental as the onset of freezing temperatures and slim pickings of natural food sources.

In late October, the International Union for the Conservation of Nature updated the status of European hedgehogs on the global Red List – a directory of species’ conservation status – to ‘Near Threatened’.

It means that hedgehogs could become even more endangered unless their decline can be halted. To understand how that can be achieved, learning how many hedgehogs there may currently be is vital.

As conservationists across the world raise the alarm for the plight of the hedgehog, here in Britain work has long been carried out to help reverse this decline.

Turning around such a historic fall in numbers is no small feat and can’t be done overnight, but earlier this year wildlife charities The British Hedgehog Preservation Society (BHPS) and People’s Trust for Endangered Species (PTES) launched the National Hedgehog Monitoring Programme (NHMP) which aims to find out how many hedgehogs there are in Britain, and how they’re faring.

This is now well underway, using a world first combination of trail cameras, AI and home-based volunteers called ‘spotters’.

Sherwood Forest and the RSPB have played their part in the NHMP already, too, as the National Nature Reserve was chosen by NHMP researchers as a site for monitoring hedgehog numbers in a woodland environment.

While our love for hedgehogs seems to be helping to stabilise the population in urban areas, where people may create Hedgehog Highways with neighbouring gardens, build nest sites ahead of hibernation, develop wild areas and log piles to provide food and shelter and leave out water and food to supplement the hedgehogs natural diet of bugs and grubs, it is a different picture outside of our towns and cities.

Woodlands are not considered to be favoured by hedgehogs, which, as their name suggests, prefer hedgerows and open areas where they can forage and hunt for food.

The decline of both hedges and food availability may be a factor in the reduction in hedgehog sightings across the British countryside.

The only way of knowing how well our hedgehog population is doing, and how numbers are changing year on year, is to understand where they are and how many there are.

The NHMP’s aim is to produce robust population estimates for the British hedgehog for the first time.

Working with BHPS and PTES and a range of other partners on the NHMP pilot scheme is Nottingham Trent University.

The University approached the RSPB, which manages the 450-acre Sherwood Forest reserve in Nottinghamshire, to undertake a month-long survey of hedgehog activity in the Forest, as part of the project.

Dr Emma Cartledge, Research Fellow in Nottingham Trent University’s School of Animal, Rural and Environmental Sciences, said: “Nottingham Trent University was really excited to be working with RSPB Sherwood Forest as part of the NHMP. As a treasured site in the Nottinghamshire countryside, Sherwood Forest made a great addition to the project.”

“Currently, not much is known about hedgehogs in woodlands. It’s not thought to be a habitat favoured by them, but one of the aims of the survey is to find out more about how hedgehogs use different habitats.”

To try and locate any evidence of hedgehogs in the forest, a total of 30 cameras were installed for 30 days across the reserve by RSPB staff and volunteers, working with project team.

Paul Cook, Warden at RSPB Sherwood Forest, said: “The RSPB is a science and evidence-led conservation charity, which is committed to protecting habitats and saving species, so we were only too happy to be involved in this project.

“The ancient oak wood pasture here at Sherwood has a variety of mammals that can be seen frequently, including deer, bats and badgers.

“Learning whether we have hedgehogs here too will help inform how we manage the forest for wildlife in future to ensure we can support their revival in the countryside.

“Much of our work is already focused on creating rides and edges, natural corridors for nature, as well as protecting our hedgerows, for wildlife.

“If the traditional farmland habitats of hedgehogs are diminishing, it may be that the reserves here can provide a rural sanctuary for them in this part of Nottinghamshire.”

With the cameras removed at the end of the month, the images were reviewed.

Artificial Intelligence (AI) is being used to remove human and blank images (such as those triggered by wind-blown vegetation), leaving predominantly animal images for home-based volunteers known as ‘spotters’ to identify online.

The NHMP team needs to know which of the hundreds of thousands of images contain hedgehogs, so volunteer spotters are absolutely crucial to the programme. 

Dr Henrietta Pringle, National Hedgehog Monitoring Programme Coordinator for People’s Trust for Endangered Species & The British Hedgehog Preservation Society said: “Using cutting-edge AI technology to help hedgehogs is a world first in hedgehog conservation, and until now there hasn’t been a rigorous nationwide survey of them – so this project is very exciting.”

“Measuring populations year on year, in the same place, will allow us to identify populations at risk, which in time will help us to reverse the decline. The results will also show regional and habitat differences, and what factors impact them in different places, which will be incredibly useful for their long-term conservation.”

“We are incredibly grateful to all of our partners and volunteer hubs who are helping to make the NHMP possible, which will make a real difference for our hedgehogs.”

And while there was plenty of mammal activity captured on camera – deer, foxes, hares and squirrels in particular, as well as curious blue tits – there were no hedgehogs.

It isn’t all bad news though. A member of RSPB staff at the Sherwood Forest Visitor Centre did report a hedgehog sighting in Forest Corner a matter of weeks after the cameras came down.  

Fay Vass, CEO of The British Hedgehog Preservation Society added: “Everyone loves hedgehogs, but we recognise that not everyone is in a position to help them in the wild.

“Becoming a ‘spotter’ for the NHMP is a fantastic way for everyone to get involved in conservation from the comfort of home.

“The buzz you get when you spot a hedgehog is just wonderful, so we hope that lots of volunteers take part.”

Sherwood hopes to be hosting more monitoring work in 2025, where more ‘spotters’ will be needed.

To find out more about the National Hedgehog Monitoring Programme, including how you can get involved as a volunteer ‘spotter’, visit www.nhmp.co.uk