Bubo vs. Ketupa
The genus Ketupa as traditionally defined is embedded within the traditional genus Bubo, while genus Scotopelia may be embedded within the Ketupa group of species, or perhaps is sister to this clade. One solution is to move all species to Bubo, which was done by some checklists in the past. Another solution is to move some species from Bubo to Ketupa, which is the solution currently favored by both the IOC and Clements checklists, and here also implemented in The Opus. The current composition of Ketupa can be seen in the genus page Ketupa.
