Yellow-billed Cuckoo Coccyzus americanus
Flight call description A series of staccato clucking phrases or gurgles, usually descending, and sometimes followed by one or more rolling "kulp" notes on a lower pitch. Many variations. Also a slow (about one per second) series of evenly-spaced, low-pitched, downward arched "cauw" notes.
Fig.1. Florida April 29, 1992 (Lang Elliott).
Single gurgle from series. Linked audio is the whole call series from perched bird
with Summer Tanager and Acadian Flycatcher singing in the background.
Examples Nocturnal
Similar species Although usually very distinctive, some variations are similar to Black-billed Cuckoo but lack that species' liquid quality. In night flight, typically gives multiple gurgle or clucking series while Black-billed gives just one gurgle call. Yellow-billed's individual gurgle calls are typically descending, while Black-billed's are typically rising. "Cauw" series is similar to a call given by Common Nighthawk on the breeding grounds. Mangrove Cuckoo Coccyzus minor, which is believed to be non-migratory in the United States, has a song that is similar to Yellow-billed Cuckoo's but has more of a nasal or husky quality, lacking Yellow-billed's hollow, wooden quality. However, Mangrove is not known to give a gurgle call like Black-billed or Yellow-billed and is not known to call in flight.
Behavior Primarily a nocturnal migrant but also engages in diurnal onward migration during spring, at least in the Gulf coast region. Flight calls are given at night, both on migration and at the breeding grounds from both perched and flying birds. Often gives flight call and song while perched at night. Not known to give flight call in diurnal flight. Flight call repertoire nearly the same as repertoire from perched birds during the day though usually abbreviated.