Hedgehogs find it hard to live in tidy gardens that have decking

He believes the hedgehog population in Wales has fallen up to 20% in the past five years.

Mr Williams, who is fronting a new series of the BBC Wales programme Iolo's Welsh Safari, wants to draw up a spot-check survey of the species.

He said: "I want people to tell me about hedgehogs they know about, have they declined or are they doing well?"

The TV presenter said the popularity of so-called garden makeovers, including the fashion for decking, is thought to be one of the reasons hedgehogs are finding it harder to thrive in urban areas.

Mr Williams, who has presented various nature series, including Birdman and Wild Wales, said: "We don't understand why there are fewer of them.

"We think we're using a lot more chemicals than we used to, we're a lot tidier around our gardens, using decking, etc. Hedgehogs don't like all of that, so they have declined.

Hedgehog numbers are in decline due to habitat loss

"Believe it or not, I have not seen a live hedgehog for almost two years now. But that may not be the same everybody, and that's what the programme wants to find out.

"Some people may know of a hedgehog population that's doing well, others may have had hedgehogs in their area in the past but noticed that they're not there now.

"If we can build up a picture of how they and doing, where they are doing well and where they're not, maybe people can do something about it."

The appeal is the first of five in the series aimed at highlighting the diversity of Wales' wildlife, as well as the dangers it faces.

Viewers are invited to e-mail their information to [email protected] or phone 0870 3334585.

Iolo's Welsh Safari is screened on BBC One Wales on Wednesday 3 May at 1900 BST.