Parrots prefer particular phrases
We have known for some time that parrots and cockatoos are excellent mimics, indeed that is where the phrase ‘parroting’ someone comes from. But the extent of each individual parrot species’ ability to mimic, and the reasons as to why they latch on to certain human words, is a subject that hasn’t been given much attention. That is until Lauryn Benedict, of the University of Colorado, and Christine Dahlin, of the University of Pittsburgh, used their time during COVID to create a questionnaire for zoos and parrot owners, asking them about their bird’s speaking habits. This questionnaire was, appropriately enough, tweeted out and gave them a sample of over 900 individuals from 73 species. They spoke to Will Tingle about why parrots like to mimic humans, and how it may provide insight into the evolution of language.
Christine - One interesting finding was that we found that a lot of the parrots are not only using mimicry extensively, they also tend to mimic sounds that are most socially appropriate. So in the wild we have hypothesised that this vocal mimicry ability allows birds to integrate into their social groups that potentially their learning sounds that are appropriate for whatever block they're currently part of. And that most of the birds that we looked at were mimicking the words and the phrases being used by the families that they're part of. So they don't tend to be mimicking as much, sounds like dogs barking or doorbells ringing or phones, things like that. It's more like, 'hi, how are you?' 'Goodbye' - the commonly used phrases in their household.
Will - So Lauryn, are you saying then that their imitation of us is them trying to integrate themselves into our social circles?
Lauryn - Yes, very much so. And that's the way that parrot flocks work in the wild is that they're large and there is, in many species, some fission and fusion of those flocks. So parrots might join new social groups over time. And the current thinking in the field is that the reason they can continue to learn vocalisations throughout their lifetime is so that if they move social groups they can begin to learn the local dialects and fit in and integrate themselves with that social group a little bit better. And interestingly, we did at one point look through some of the voluntary responses telling us the words that birds used most often. And a lot of those words were words you would expect, like 'good bird', 'step up', things like that. But there were also a few swear words in there, <laugh> and at least a few parrots have learned to say 'Alexa' and various other things that are probably pretty interesting because they hear their humans say them all the time.
Will - That's great and dystopian in equal measure. Now humans as our vocabulary expands, we can theoretically learn words from now until our very last day. But is this the case with parrots? Does their vocabulary expand as they get older?
Christine - The one species which we had a sufficient sample size to examine that question was the African grey. For the African grey. It seems that they are able to expand their vocabulary up to about five years of age and then after that it pretty much levels off. So potentially they are replacing words in their vocabulary or sounds that they're no longer using as they gather new ones. And we suspect that this might be useful if birds in the wild are doing something similar. Maybe if they have moved to a new social group they can replace no longer used words, or part of their call repertoire, with a new one.
Lauryn - But they certainly can learn later in life. So a 50 year old parrot absolutely can learn new vocalisations. They just don't seem to keep expanding their repertoire. So maybe when they learn that new vocalisation, they drop something else out of their repertoire.
Will - This may be a bit of a sideways leap or a bit of a stretch, but do you think that this could show us perhaps how language conform, obviously with humans will never truly know and there's only one species and it was a long time ago, but perhaps human speech and vocabulary started out as a series of just imitations. What scope is there do you think, for this study to open up into perhaps the development of language in another species?
Christine - I feel like there's lots of elements to human language that we can see in parrots and indeed in other animals. Like one aspect is referentiality, that's the ability of sounds to refer to specific elements or reference in the environment. I mean, even in our study we can see context specific usage of the bird's calls and there's lots of animals that will refer to different predators with different calls. So that's an aspect of human language. One aspect of parrot language that I've studied in wild parrots, in yellow-naped amazons, is syntax. So syntax are specific rules that you use to govern how you put long strings of vocalisations together. Yellow-naped amazons give complex duets in which males and females precisely coordinate their calls in certain ways. They put certain types of calls at the beginning, they time their calls in specific ways. And so these rules are really important for the structure of these calls.
Lauryn - And there are some pieces of human language that we don't see in parrots. Things like the ability to rearrange words almost infinitely to make new meanings all the time. We certainly haven't demonstrated anything like that in parrots and we don't know that they always have an understanding of the meaning of the words that they say when they say them in context. That would be a future thing that I think researchers, you know, should try to look into. And of course there's great work with like Alex, the African grey, on questions to do with cognition and really understanding of what they're saying. But certainly that ability to make really clear mimicry of particular sounds so that groups can have shared sounds and the ability to use them in the right context is sort of a really interesting stepping stone to things like potentially more complex language like communication.