Higher-order semantic structures in an African Grey parrot’s vocalizations: evidence from the hyperspace analog to language (HAL) model

Comparing the productive vocabularies of grey parrots (Psittacus erithacus) and young children

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.

Avian cognition and the implications for captive parrot welfare

Previously assumed to be unintelligent animals, many species of birds display high levels of cognition and may even possess conscious awareness. In particular, both corvids and parrots have been the focus of cognitive research including studies on problem-solving, social intelligence, and sentience. Despite their similar neural architecture and cognitive abilities, the laws regarding these two families of birds differ greatly. In the United States, it is illegal to keep corvids as pets. Parrots, however, are one of the most commonly kept pets in America, although their care in captivity remains largely unregulated. Captive parrots suffer from a number of medical and psychological issues and experience high rates of neglect and abandonment. At the same time, wild parrot populations are dwindling due both to habitat loss and capture for the pet trade. This review examines the novel findings on avian cognition and applies them to the potential ethical implications of keeping parrots in captivity. In addition, suggestions for future directions are presented, including the development of legislation to protect captive and wild parrots.