This may seem like an absurdly common occurance, but for me, it isn't. For whatever reason, sparrows are generally completely uninterested in my feeders. They may occasionally prowl around the ground under my landlady's feeder, but they come up on my deck once in a blue moon, and leave quickly.
And yet, suddenly, these last few days, not having changed the food at all, the sparrows are appearing, tiny little brown shapes hopping in among the hulking doves.
I would suspect the new jury-rigged dripping birdbath (i.e. a bottle with a hole in it dripping into a trough) was attracting them, but they aren't using the birdbath at all. (Hardly anything is. Perhaps it's too cold, or perhaps they just hate it.)
But there they are, sparrows. Huh.