The study into the familiar garden animal found they were declining in both rural and urban areas, with evidence now “very strong that hedgehogs are in trouble”.
Conservation groups issued the warning over the plight of the mammals – already listed as a species in need of conservation action – as they launch a scheme to encourage people to make their gardens and neighbourhoods more “hedgehog-friendly”.
The report by the British Trust for Ornithology (BTO) for the People’s Trust for Endangered Species (PTES) and the British Hedgehog Preservation Society (BHPS), looked at a series of surveys which all showed hedgehog numbers declining in recent years.
The research also indicated the mammal has suffered huge long-term declines across Britain, numbers falling from an estimated 30 million in the 1950s to just 1.5 million by 1995.
Conservationists say hedgehogs have been hit by the loss of habitat such as hedgerows and grassland, more intensive agriculture, the use of pesticides which have reduced their food and the presence of more badgers in the countryside.
According to the groups, badgers are a natural predator of hedgehogs and also compete for other food with them, and the smaller mammals will avoid sites where badgers are present in large numbers.
Urban and suburban areas are becoming increasingly important for hedgehogs, but tidier, more sterile gardens divided up with impassable fences and walls also pose a problem for them.
Members of the public are being urged to get involved with the Hedgehog Street campaign, which includes taking simple steps to make their gardens more hedgehog-friendly.
Measures include providing hedgehog houses, leaving rough, untidy patches for shelter and planting hedges instead of fences or walls, or even making holes in existing barriers.
Fay Vass, chief executive of the BHPS, said: “Gardens have become far too tidy in recent years, paved over for parking, or enclosed within impenetrable fences and walls. Hedgehogs typically travel about a mile each night in order to gather food and search for a mate, so they need the freedom to move between different areas.
“Relatively simple actions will ensure success for the survival of these increasingly threatened creatures.”
More information about the campaign can be found at www.hedgehogstreet.org.