Branch of zoology dealing with the study of birds. Early writings on birds were largely anecdotal (including folklore) or practical (e.g., treatises on falconry and game-bird management). From the mid-18th century on, ornithology progressed from the description and classification of new species discovered in scientific expeditions to the examination of internal anatomy to the study of bird ecology and ethology. Ornithology is one of the few scientific fields in which nonprofessionals make substantial contributions; the field observations of birders provide valuable information on behaviour, ecology, distribution, and migration. Other information is gained by means of radar, radio transmitters, portable audio equipment, and bird banding, which provides information on longevity and movements.