The Cornell Laboratory of Ornithology's Project Feederwatch is a nationwide experiment to determine the feeding preferences of backyard birds. For example, one of the best ways to lure the American Goldfinch to your feeder is to provide thistle or Niger seed. Don't count on seeing Northern Cardinals at your thistle feed, however. Their preference is for sunflower and safflower seeds. Different birds also feed in distinct ways.
Some birds prefer to feed on the ground, others on elevated platforms.
Eastern Bluebird Keeping a log of feeder activity is a great way to track the annual changes that many birds experience. The reason, of course, is that the males are trying to impress the females. One of life's greatest thrills is to see a flock of Evening Grosbeaks descending on your feeders. Besides eating you out of house and home, these large finches are spectacularly colored and make quite a racket in large numbers. Don't count on seeing them often, however.