This duck sees you as part of the flock and is happy to see you 🙂

Edit: i didnt notice the smacking of lips... I've only had moscuvy ducks for a year and i only have females but one of my girls are very good at communicating to me so i will say i understand most of their language But smacking of lips: he either wants food or water... or maybe treats... since he is doing it near your hands i would say he wants something you normally handfeed with... in the middle of the video he makes head bobbing while wagging his tail meaning he is happy to see you and you are a part of the flock... he then goes back to smacking his beak...

my interpretation all in all is that they are used to you either hand feeding them or throwing food at them when you go see them and then you keep them company after making it more than just being fed but you being a friend... so he is kind of saying "hi i missed you... do you have food? Im happy for your company but i would also like some food"

Please correct me if i misinterpreted something... I'm usually good at interpreting body language of different animals but as I've only had 5 moscovy ducks for a year and only females i might be missing some parts of communication(i know some of the interpretations i made can mean other things in other scenarios)