Terry Pratchett warns Britain's hedgehogs and sparrows are dying out The author was speaking at Secret World Wildlife Rescue Centre, in East Huntspill, Somerset, which is the site of the proposed centre. Sir Terry was joined by television naturalists Mike Dilger, Simon King, Steve Backshall, Chris Packam and Michaela Strachan in backing the Call of the Wild Appeal to raise money for the hospital. It will include an operating theatre, examination, preparation and x-ray rooms, with a first floor laboratory, lecture theatre and library. It would give Secret World, Britain's only 24-hour animal rescue centre, the facilities to provide all veterinary care on one site and bring faster relief to suffering wildlife. A computer link would allow up to 120 resident students a year to watch procedures being performed by the hospital's in-house veterinary surgeon in an operating theatre. Sir Terry, who is suffering from early-onset Alzheimer's, previously offered a £10,000 reward to catch a swan killer - who massacred 30 of the birds in Somerset last year. The author is also campaigning for the right to die and has funded the Commission on Assisted Dying which says assisted suicide should be allowed for those who are mentally competent.