Hi Kirsty1
You might be better off putting your question to the people who look after the Big Hedgehog Map. I imagine For general enquiries, email hedgehog@ptes.org would be the best place to enquire.
But bear in mind that where there is one hedgehog, it’s very likely there are more, so it’s possible that someone else has reported a, different, live hedgehog in the area.
Sorry to hear you found a poor dead hedgehog – not a pleasant experience – but well done for putting it on the Map. Hopefully you will see some living ones as well.
Good luck.
