Among mammalian groups, such undisputed evidence is present for several whales, dolphins and pinnipeds, bat species and elephants. Nevertheless, there is agreement that strongly deviating vocalizations in animals reared in isolation, the imitation of sounds of other species, and/or the presence and imitation of individually distinct vocal variants within a species demonstrate the presence of vocal learning. This independent occurrence provides important opportunities for comparative studies on mechanisms, function and evolution of vocal learning, which may also shed light on the mechanisms and evolution of vocal learning in our own species.Дefinitions of vocal production learning vary among researchers and, along with that, the type of vocal modifications that are considered evidence of vocal learning (e.g. However, vocal learning has evolved in several other animal groups, in which it may have arisen independently. ) and modifications and deviations from normal species-specific vocalizations seem only possible within relatively tight species-specific constraints. There is ample evidence that primates of various species raised in social isolation or cross-fostered to other species develop largely normal species-specific vocalizations (e.g. The extent of the human ability to imitate and adjust vocalizations based on auditory experience or some form of feedback shows a major difference with the vocal learning abilities of other primate species, including the great apes. acquiring vocalizations through learning, is a crucial component of human speech and language development. This article is part of the theme issue вЂVocal learning in animals and humansвЂ™. The observations support the hypothesis that vocal learning in birds evolved in several groups independently rather than evolving once with several losses. We discuss the rearing conditions that may have given rise to the imitations and suggest that the structure of the duck vocalizations indicates a quite sophisticated and flexible control over the vocal production mechanism. Together with earlier observations of vocal differences between populations and deviant vocalizations in captive-reared individuals, these observations demonstrate the presence of advanced vocal learning at a level comparable to that of songbirds and parrots. Sounds of different origins could be combined in one vocalization and at least some of the imitations were memorized at an early age, well before they were produced later in life. The hand-reared male used at least three different vocalizations in the display context, with each one produced in the same stereotyped and repetitive structure as the normal display sounds.

The imitations were produced during the males' advertising display. These sounds have been described before, but were never analysed in any detail and went so far unnoticed by researchers of vocal learning. A hand-reared individual imitated a slamming door and a human voice, and a female-reared individual imitated Pacific black duck quacks. Here, we provide evidence for vocal learning in a member of a basal clade of the avian phylogeny: the Australian musk duck ( Biziura lobata). For birds, oscine and some suboscine songbirds, parrots and hummingbirds demonstrate this ability.

Acquiring vocalizations by learning them from other individuals is only known from a limited number of animal groups.

Mimic duck goose goose duck