Which birds usually do much more harm than good in gardens that I should be watching out for.
I don't want to be taken by surprise!
Well personally I can't stand cowbird's because they knock other birds eggs out of their nest. What jerks! Starlings are also annoying because they eat all of my berries.
Yeah I agree cowbirds are bad, and they're ugly and they eat your food too.
Perhaps you could clarify your question? Do you mean which ones eats most of your berries/plants, which ones make a mess, or what?