Mr Challis, who lives on the south Shropshire border, supports Tusk, which fights to halt the illegal ivory trade. He is also the patron of the Clee Hill-based British Hedgehog Preservation Society.
Today Mr Challis found himself in a prickly row with a rival animal charity – after it used pictures of hedgehogs to try to raise money, even though it is supposed to look after birds.
The Royal Society for the Protection of Birds has been using cute hedgehogs, rather than birds, in an attempt to boost its coffers. It is selling cuddly hedgehogs at events and using images of them in its advertising – despite not funding research to help protect the prickly mammal.
Today Mr Challis said the RSPB should stick to using birds, not hedgehogs, because it would divert money away from his chosen charity.
He said: "This is all wrong, it's all very unfair. The RSPB supports birds and does a very good job. I'm sure many, many people across the UK applaud and support its work. But there's a clue in the title – 'birds' – and the RSPB should stick to that, rather than using hedgehogs to promote itself. Hedgehogs need our support too – and people might mistakenly think that the RSPB is doing something to support them when, of course, it is not.
"It's quite simple: birds for the bird charity, hedgehogs for the hedgehog charity. Let's keep it at that and then nobody is confused."
Mr Challis added that the RSPB's use of hedgehogs was "very peculiar" when there are so many birds under threat.
And garden designer Jenny Steel, from Shropshire, claimed that the RSPB's "ridiculous" adoption of the hedgehog would divert cash away from specialist charities.
The RSPB has said it had discussions with other bodies about saving nature, "collaborating on research, reserve management and on persuading others to act".