Comparing human with non-human animal vocalizations can give insight in evolution and mechanisms of vocal behavior. This study addresses rhythm, a feature shared between speech prosody and music, in Southern Ground Hornbills (Bucorvus leadbeateri). Adults in this bird species sing a rhythmically coordinated duet, alternating between the male and the female. Vocalizations were recorded in two developmental and social settings in zoo living Southern Ground Hornbills and analyzed for their rhythmic patterns. Preliminary results indicate juvenile Ground Hornbills produce similar calls as adults, but do not produce the rhythmic duet yet. Moreover, upon introduction of a new adult male to an adult human-reared female, the birds did occasionally, but not always produce a rhythmic duet. These preliminary findings suggest that either learning and/or physiological changes during development and possibly pair bonding induce the rhythmic duet. Further research using more diverse settings and longitudinal recordings (including more adult controls), should disentangle these possible mechanisms. These findings are relevant for both evolution and mechanisms of rhythmic capacities, as well as animal welfare, particularly breeding programs to reintroduce Ground Hornbills to the wild. If development of the coordinated duet is in jeopardy, the breeding and reintroduction may be at risk as well.