Book excerpt: The relative attractiveness of various seeds used to feed wild birds was measured. This information, with data on consumption rates and costs, provides a basis for determining the most efficient materials for use in bird feeders in residential areas. Many common bird foods, such as fine cracked corn, wheat, sorghum, hulled oats, and rice, were found to be relatively unattractive. Seeds of the small black oil-type sunflower were superior to those of the black striped and gray striped sunflowers. White proso millet was the best seed for use in attracting the small seed-eating species. Feeding preferences among various species of birds are strikingly different; consequently it is difficult to formulate a mixture of seeds that would be efficient at all locations and at all times.