I'm also a casual birder, ID'ing the local birds around the feeders I put up. I now have only a sunflower seed and a thistle seed feeder. The house finches, goldfinches, and the chickadees like them, but the sparrows not so much. This is a good thing because when I had a feeder with a mix of seed, it was dominated by literally dozens of house sparrows (VERY prevalent around here), and the associated mess.