Complex sentence: It is frequently assumed, based on temperate-zone birds, that only the males sing; however, in 2009, Price, Lanyon, and Omland conducted a study that shows that both males and females of many tropical orioles sing.
Split into simpler sentences: It is frequently assumed, based on temperate-zone birds, that only the males sing. However, in 2009, Price, Lanyon, and Omland conducted a study that shows that both males and females of many tropical orioles sing.