Vocalization structure and its possible function in the brown- headed parrot Poicephalus cryptoxanthus [abstract]

Vincenzo Venuto and Renato Massa (1997). Vocalization structure and its possible function in the brown- headed parrot Poicephalus cryptoxanthus [abstract]. Bioacoustics, Volume 8 (3-4): 268
Abstract: 

Today there is evidence that parrot vocalizations and even parrot mimicry are highly functional. In addition, there are also data suggesting that parrots may be able to use assemblages of short sounds, normally used in a given context, to built up more complex vocalizations that may be used in a different context. To investigate this possibility, we studied vocalizations and associated behavioural patterns of the brown-headed parrot Poicephalus cryptoxanthus, a South-East African species, kept in pairs in captivity at our African Parrot Centre of the University of Milan. By analyzing a total of 12 hours of recordings by means of the "Canary'' program of the Cornell Laboratory of Ornithology, we recognized seven main types of calls that may be separated in the following groups: a) short antagonistic calls associated with an imminent attack or a warning to disperse, b) nestlings' calls mainly consisting of food begging, c) sexual interactions, that is courtship, duetting, preening and courtship-feeding. The latter are also the longest and most complicated calls. They are composed of a total of 10-13 syllables that may be assembled in different notes which, in turn, may be further assembled in a song that may consequently be highly variable and may even last for 78 seconds. These long and' complicated songs are usually uttered as a duet by the members of a pair, probably to consolidate the ties between male and female. These findings further support the hypothesis that some parrots may maintain their monogamic pair-bond through the performance of a pair-specific courtship song that, in some species, such as the African grey, may also include the mimicry of heterospecific sounds.