Parrots have a remarkable ability to mimic human speech. You have witnessed them sing in heavy metal bands and made them the pet of choice to deliver punchlines in pirate movies. Part of this is just being able to make the sounds that we do. But how do they do that and many other living species cant, for instance, Monkeys and Apes are more alike to humans in terms of features, still you won’t find and monkey to even speak a single word clearly?

Articulate Tongue and Vocal Learning Ability

Parrots have articulate tongues, which can move around in their mouths and shift frequencies to make human-like vowel sounds, but mostly parrots have unique brains. When the majority of birds chirp or sing, they’re making noises that are hardwired, but parrots can create new vocalizations, which scientists call vocal learning. Not only that, but something about their neurons makes them incredibly good at vocal mimicry, replicating the sounds or calls of other species.

Other birds having similar capability

Only three types of birds are capable of vocal learning: hummingbirds, songbirds, and parrots. Scientists don’t know exactly how vocal learning helps them, but freestyling might let different groups of birds tell each other apart, which could help them identify enemies and form strong social bonds. Despite being very different birds, hummingbirds, songbirds, and parrots all have seven clusters of neurons in their brain called song nuclei. Since other birds don’t have these brain regions, scientists think they’ve got to be behind vocal learning. The song nuclei are surrounded by or next to parts of the brain that control movement. The ones involved in learning are towards the front of the brain, and those involved in sound production are farther back.

Figure 1. Cortico-cerebellar pathways in birds and mammals. In mammals, inputs from the cortex to... [+] the cerebellum are routed through the pontine nuclei. In birds, inputs from the telencephalon to the cerebellum are also routed through two nuclei in the base of the pons (medial and lateral pontine nuclei, PM and PL) but also through an additional nucleus in the pretectum, the medial spiriform nuclei (SpM). In mammals the cerebellum, through the cerebellar nuclei (CBN) sends projections back to the thalamus, which in turn projects to motor and associative areas of the cortex. In birds there also a projection from the cerebellum to the thalamus but this arises from the lateral cerebellar nucleus. In turn, these regions of the thalamus projects the nidopallium caudolaterale (NCL) (the avian analogue of the prefrontal cortex of mammals), and the rostral Wulst (the avian equivalent of motor cortex). (doi:10.1038/s41598-018-28301-4)

But just having song nuclei doesn’t explain why parrots are so much better at, well, parroting speech. Now, most research on mimicry and parrots uses the common parakeet or budgie as a model for the whole group, but in 2015, researchers took a look at the brains of a bunch of different parrots and found that they all had something that hummingbirds and songbirds didn’t: an extra layer, or shell, surrounding each nucleus. It’s a bit like the candy coating on a skittle. Parrots have the full candy, while other birds just have the fruity core. And differences in the number of shells seem to correlate to mimicking abilities. Expert imitators like the African Grey parrot have much larger shell regions and smaller cores than copycats who are less skilled like budgies and peach face lovebirds. So far, it’s just a correlation, so these shells may not be the reason—or the only reason—why parrots are super mimics.

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