Bird-keeping and the development of ornithological science

We review the growth of knowledge in several areas of ornithology, and demonstrate the important, but largely unrecognized role of European bird-keeping in the development of several different areas of bird study. By ignoring the early bird-keeping literature, historians of ornithology have overlooked many significant observations. There are several reasons why the role of bird-keeping has been ignored, including the shifting boundaries of scientific ornithology and the varying relationship between bird-keeping and ornithology. We review the significance of observations of captive birds to ornithology and show that they have made important and previously unrecognized contributions to the following aspects of bird biology: song acquisition, function and anatomy; territory; breeding biology; external genitalia; migration; instinct and learning.