What is the fine-grained topic of the following text: The main changes were the addition of Urrao Antpitta, and the splitting of Horned & Sira Curassows; Hen & Northern Harriers; Common & Cape Verde Buzzards; Banggai, Oberholser's & Sula Fruit Doves; Philippine, Everett's & Negros Scops Owls; Northern & Mexican Barred Owls; Pacific, Salim Ali's, Blyth's and Cook's Swift; Dull-mantled & Magdalena Antbirds; Hair-crested & Tablas Drongos; Grand Comoro & Moheli Bulbuls; Nightingale Reed, Saipan Reed & Pagan Reed Warblers; Streaky-breasted & Bornean Spiderhunters. Only return the topic.
Bird species classification changes