This variation and complexity of behavior and ecology provides much fodder for field biologists. Studies of bird biology have resulted in many general evolutionary, ecological, and behavioral principles. These studies of learning were extended to the natural setting with Lorenz's studies of imprinting, and with later studies of learning of song in many species of birds. Recent studies have shown that many bird species are capable of long-term spatial memory, for instance species that cache food for use during the winter, most notably jays and their relatives. The methods by which birds obtain food are as diverse as the types of food they prefer.
Many species use visual cues to locate fruits, seeds, and insects.
Bird species that forage for flying insects on the wing, such as swallows and flycatchers, are agile and swift flyers. Many other insectivores are gleaners, searching for insects in vegetation or on the trunks of trees. We will observe a number of different strategies used by fish-eating birds. Some hover above a body of water and dive in, others wade and jab, and still others swim at or under the surface of the water. Some species specialize in stealing the prey of other species.