Complex sentence: Historically, there were once two species of koa-finches, "Rhodacanthis palmeri" and "R. flaviceps," which fed on green koa seed pods, though these species are now extinct due to habitat loss and avian malaria.
Split into simpler sentences: Historically, there were once two species of koa-finches, "Rhodacanthis palmeri" and "R. flaviceps," which fed on green koa seed pods. These species are now extinct due to habitat loss and avian malaria.