melierax canorus or musicus
Webster's Dictionary (GCIDE)
Chanting \Chant"ing\ (ch[.a]nt"[i^]ng), n. Singing, esp. as a chant is sung. [1913 Webster]
Chanting falcon (Zool.), an African falcon (Melierax canorus or musicus). The male has the habit, remarkable in a bird of prey, of singing to his mate, while she is incubating. [1913 Webster]