Naturalists tend to look back to the written tradition rather than common usage to supply official bird names. Zealous regularization has its drawbacks. Like gardens that have been only recently planted, highly regularised bird names take time to become properly established. Common names' based on the scientific taxonomy also risk being made obsolete by advances in scientific knowledge. What is scientifically accepted today may not be accepted tomorrow.
Taxonomic changes can even give rise to divergences between languages.
The Strigidae again provide a good example. Chinese ornithologists recognise a difference between the genus Bubo and the genus Ketupa , reflected in the standard names, namely 'eagle owls' for Bubo and 'fish owls' for Ketupa . Vietnamese ornithologists treat all members of Bubo and Ketupa as belonging to Bubo , calling both types . In other words, the difference between Chinese and Vietnamese names is related more to the scientific dialect of the 'surveyors' than to any real difference between the two languages. Since the popular names are very important in developing a healthy system of bird names, I've started each family or sub-family in this list with a section called 'General names,' in which normal layman's usage is described briefly.