Black-billed Cuckoo
Coccyzus erythropthalmus
Adults have a long, graduated brown tail and a black, slightly downcurved bill. The head and upper parts are brown and the underparts are white. The feet are zygodactylous. Juveniles are drabber and may contain some rufous coloration on the wing. The adults have a narrow, red orbital ring while the juveniles' is yellow. Black-billed cuckoo chicks have white, sparsely distributed, sheath-like down that contrasts heavily with their black skin. Voice: When they are a couple of days old, the chicks can make a buzzing sound that resembles an insect and a few days later, they can make a low barking call when disturbed. The call of this species is 2–5 sets of "coo" notes that are high-pitched, rapid, and repetitive. There is a slight pause between each set. The phonetics are often written "coo-coo-coo-coo, coo-coo-coo-coo, coo-coo-coo-coo, ...".
ID text from Wikipedia, CC BY-SA 4.0
Yellow-billed Cuckoo
Coccyzus americanus
Adults have a long tail, brown above and black-and-white below, and a black curved bill with yellow especially on the lower mandible. The head and upper parts are brown and the underparts are white. There is a yellow ring around the eye. It shows cinnamon on the wings in flight. Juveniles are similar, but the black on the undertail is replaced by gray. The adults show no sexual dimorphism, and thus the males and females can't be told apart by plumage. Measurements: Length: 10.2-11.8 in (26–30 cm) Weight: 1.9-2.3 oz (55–65 g) Wingspan: 15.0-16.9 in (38–43 cm)
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
Learn this pair in BeakBrain
Photo and call practice, free in any browser.
Play BeakBrainPhotos and recordings are credited to their authors under the licence shown. Full profiles: Black-billed Cuckoo and Yellow-billed Cuckoo.