Complex sentence: Lear's macaw was first described by French ornithologist Charles Lucien Bonaparte in 1856, but in 1978, the rarely seen bird was considered a distinct species when ornithologist Helmut Sick finally located the wild population.
Split into simpler sentences: Lear's macaw was first described by French ornithologist Charles Lucien Bonaparte in 1856. But it was in 1978 that the rarely seen bird was considered a distinct species when finally ornithologist Helmut Sick located the wild population.