One of the things birders both love and detest in equal measure are splits – i.e., when a bird species is split into two different species. While this may mean an increase in bird lists and ‘lifers’, this also means a headache in identification. Birds differ significantly from one place to the other and taxonomists have the problem of figuring out whether the difference in coloring warrants a new subspecies, species, or dismissal as just a local variant. If I may be allowed to backtrack to popular culture, the well-named Birder’s Guide to Everything is proof of this conundrum. (Birding club. Birds. More birds. Romance involved; can be dismissed. DIscussion of ethics in birding to some extent. Birds. Need I say more?) An unusually patterned duck, in this case, is far too similar for comfort to the extinct Labrador Duck, and serves as the plotline of the film.
If this can drive an entire movie, you can tell this is somewhat of an issue.
The Oriental Cuckoo is one example of this. While perhaps not the most exciting one, it illustrates neatly what happens far too often for many species. Formerly a supspecies under the rather generic ‘Himalayan Cuckoo’, differences in size and sound led to it being split from it. The bird above got stuck with Himalayan Cuckoo (Cuculus saturatus), while the slightly larger Oriental Cuckoo (Cuculus optatus) became a new species. In fact, a third species was split as well – the darker Sunda Cuckoo became Cuculus lepidus.
Of course, differences in range, commonness (that is a word), and other associated factors often abet in identification. Still, you can get bogged down for years in the vast labyrinth of taxonomy. Birds are wonderful. Identifying them – not so much.