Do swans understand the concept of "Hello" & "Goodbye"?

That's fascinating, Nathan. Birds may not be able to speak our language but non verbal communication is often seen between animals of the same species. Good evidence that it can also work between different species. I shall have to try it when I next encounter swans.

Well they certainly seem to be acknowledging you Nathan. Nice video

Hi Nathan, lovely video clip and interesting too; there is so much we still don't know about animals and the abilities to communicate with them in some way whether it is a simple pattern of routine they get used to and therefore learn to trust us or a deeper meaning; When birds get used to seeing you, especially if food is involved, they will put enormous trust in us and recognise us as no threat; I've been privileged to have had a Great Spotted Woodpecker almost at my feet and a Wren on my lap when in the garden when I've had live mealworms to offer them. The birds are not "trained" to come so close, they just learn to trust and the focus is food, especially when they have young to feed, You learn a lot from birds, as you have done and proven, by simply spending time with them and observing birds and their characteristics. Even when birds look very similar, you can often pick out which is which when you have spent quite some time studying them and can almost anticipate what they may do next ! Thanks for sharing such a lovely story and clip.    

Hi Nathan
You're right on the nodding heads. A local pair that I've known for around 6 years now always do it when they see me. Their cygnets copy them too, so last year at one point I had 8 bobbing/nodding heads coming my way. You may also notice that they snort (a few quick snorts in succession) when they are happy, usually just after being fed, which seems to be something akin to our "thank you, or, I like you". They only do it in certain situations and it definitely seems polite/affectionate.
My favourite is their "elephant" esque rumble they do though that is nowhere near as common, at least not with the 2 I am close with.
They also recognize sound. I can call the swans over to me from anywhere inside their hearing range. As soon as they hear they start looking until they see me and then they come. I always use the same word, the name I call the cob, but they all answer to it. When I find someone I can trust with them I want to try an experiment. Get them to call using the same word. I'm very interested to see if it's just the sound they react to, if they look, if they come when they see where the sound is coming from and would they come out of the water when they see it's someone they don't know as well. If they don't their response isn't just based off a familiar noise and suggests a far higher intelligence than many give them credit for.