One of the closest relatives of the Guira cuckoo is the Common cuckoo (Cuculus canorus), found e.g. in Sweden. In some respects, these birds are similar. But most things are different. The Guira cuckoo, e.g., emits a strong, pungent odour, like several of the birds in the subfamily Crotophaga. Neither is it a nest-parasite, like the Common cuckoo. Instead, very much like the Smooth-billed ani, it may at times have collective nests with up to twenty eggs. It subsists from hunting small animals like arthropods, insects and even frogs, and by stealing eggs from other birds' nests. It sings in a series of high-pitced whistles that at the end turn into a raspy cawing.