Of 12 released into the wild in Surrey, only three were definitely still alive 15 weeks later, the research found. The animals dispersed widely - over distances up to 3km.
Six died in accidents, including three hit by cars, while one, having done well for 71 days, drowned in a steep-sided garden pond. One became the unlucky victim of a badger.
Dr Nigel Reeve, a lecturer and researcher at Roehampton Institute, London, who carried out the study, wrote in Nature Line, the magazine of Surrey Wildlife Trust: "We must be very concerned that a hedgehog's life seems to be so dangerous. Of seven recorded deaths, only one was the result of a failure to thrive and all other mortality was accidental."Reuse content