ocr: UNUSUAL CALLS Ina a spectacular courtship display, the male blue bird of paradise drops upside down on an open perch. His blue belly and flank feathers fan our, and by thythmically vibrating a patch of plumage, the bird generates a throbbing, machine-like sound. BLUE BIRD OF PARADISE e LAUGHING LITTLE KOOKABURRA WATTLEBIRD EURASIAN EURASIAN CUCKOO NIGHTJAR EURASIAN e MONTEZUMA'S BITTERN OROPENDOLA % % 880 - 8090 - d 80 - > 380 6 88 e - - e 8 6 0 - - a * - 0e X - e
