Search

Due to their outstanding ability of vocal imitation, parrots are often kept as pets. Research has shown that they do not just repeat human words. They can use words purposefully to label objects, persons, and animals, and they can even use conversational phrases in appropriate contexts. So far, the structure of pet parrots' vocabularies and the difference between them and human vocabulary acquisition has been studied only in one individual. This study quantitatively analyses parrot and child vocabularies in a larger sample using a vocabulary coding method suitable for assessing the vocabulary structure in both species. We have explored the composition of word-like sounds produced by 21 grey parrots (Psittacus erithacus) kept as pets in Czech- or Slovak-speaking homes, and compared it to the composition of early productive vocabularies of 21 children acquiring Czech (aged 8–18 months), who were matched to the parrots by vocabulary size. The results show that the 'vocabularies' of talking grey parrots and children differ: children use significantly more object labels, activity and situation labels, and emotional expressions, while parrots produce significantly more conversational expressions, greetings, and multiword utterances in general. These differences could reflect a strong link between learning spoken words and understanding the underlying concepts, an ability seemingly unique to human children (and absent in parrots), but also different communicative goals of the two species. [ABSTRACT FROM AUTHOR]

Parrots belong to the handful of animal species capable of vocal production learning. They are considered to be open-ended learners with complex and variable vocalizations. It is not known, however, to what extent their repertoires are shared among individuals within a group or between vocally isolated individuals or groups. In study 1, we mapped the repertoire of four captive African gray parrots (Psittacus erithacus) using a combination of three acoustic analyses. In study 2, we compared the repertoire of two female African gray parrots from two different laboratories who had never been in vocal contact with each other or any member of the other parrot's social group. Results of study 1 showed a relatively large agreement between all three methods used to analyze the vocalizations. Almost three quarters (72.8%) of categories determined by visual-acoustic analysis were confirmed by at least one of the two computer-aided methods used, i.e., by spectrographic cross-correlation and/or a multiparametric statistical method. In study 2, we found a relatively large proportion of calls shared between the repertoires of the two gray parrot subjects. Over half and over a fourth of calls produced by parrots with the smaller and the larger repertoire, respectively, were shared between the two. No previous study identified such a large proportion of intergroup shared calls within this parrot species. It seems that some calls tend to reappear in vocally isolated groups based on inherited predispositions, similarly as has been documented in songbirds. [ABSTRACT FROM AUTHOR]