That is, some individuals feed at favoured sites and others feed along the periphery. If chickadees nested in your garden, the resident pair outrank the others and have the favoured sites. Several white-throated sparrows may visit your feeder. Look carefully and you will see that some individuals have a small yellow spot in front of the eye. These birds outrank those that lack the yellow spot and have the favoured feeding sites.
Many birds store food.
Chickadees, nutchatches and blue jays will take sunflower seeds from your feeder and store them in crevices in tree bark or under the shingles of your house. In mid-summer a few years ago, I watched workmen replace the roof on a neighboring house. As they removed the old shingles, they were continuously harassed by a half-dozen chickadees that had stored sunflower seeds under the curled shingles the previous winter. On woodland walks you may see group of birds made up of different species. The larger numbers of birds improves the chances that the flock will find good feeding sites.