Yes, house sparrows used to be everywhere when I was a kid. When we moved out of London to Hampshire (about 20 years ago) we had a huge number here too. For some reason they disappeared over night about 5 years ago.
One theory for the decline is modern houses do not have such good nesting opportunities, but the houses round us are older and were supporting the population, so it can't be that.
Very strange, I'll have to read about that and see if that is true in most places. I have a few here in this house I live in now, but they are not a problem, my problem is squirrels, I don't even care if the sparrows eat birdseed now, as long as there is not 1 million of them.
Thanks for that information.