it's sad but true, my 18th month old son knows what things are though, I always have him out for walks round the coutryside and point him the animals out, we actually have a 4ft fish tank filled with tadpoles and baby frogs at the minute and he can tell the difference, he even trys to say there names, we did have some baby birds in a nest again but the mapies had there way - again! my son can say 'naughty magpie' while wagging his finger which is good!
It's the kids in london what have it worst, places like that - some have never seen a cow, shame.