Hi Kenneally
Where do they get the idea there are none? Simply from the fact that a) many people have surveyed areas where they were found without seeing them and b) if, indeed, they are present, people don't take the trouble to report their sightings at, for example,
http://www.herpetofauna.co.uk or
http://www.arguk.org.
There are not enough amphibian and reptile conservationists to survey everywhere often enough - reports (with photographs) from ANYBODY are essential.
Chris