The story about the pool frog is interesting. It is said that it is native to England but very rare. It says there are only a couple of colonies left, somewhere down south. But i have seen one in the North West in a big pond. I didn't know what type of frog it was at the time, some person who specialises in native amphibians thought it was a non-native species and wanted rid of it. So i caught it and put it in my pond, it stayed for a few months and then disapeared. It loved to bask in the sun.