Trained raven interracting with it's owner

I had always heard that ravens, being of high intelligence, are able to be trained. There's the old image of Vikings having trained ravens, and apparently it's very true. The raven is a big part of Norse and Celtic mythology in particular. When listening to ravens where I live, I have often detected a myna bird-like vocalization; but what I didn't realize is that ravens can mimick sounds perfectly, like human voices, as you can see in this video. The ravens that I come into close contact with are perhaps twice as large as this bird, although it may not be full grown yet.

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