coffeeking
And your experience is what? Anecdotal?
You have two cats, it's hardly a representative sample is it?!
The British Mammalian Society study was based on 986 cats living in 618 households. Not conclusive I grant you but better than 'my two shat in my own garden'
In a five month period the moggies in the report took a total of 14370 species. I think that even if someone would have wanted to skew these results then the skewing would be down not up with cat owners hiding the fact that they are in charge of a very efficient killing machines.
My guess is that cats may be one of the main drivers in urban areas for causing population collapse in a wide range of fauna – I say collapse as I recognise cats as not the only culprit but the ones likely to finish the job off – I'm sure someone can come up with scientific proof on that one.