It’s hard to discuss bird behaviour without projecting human values, behaviours and emotions on them. Are birds happy? Playing? Angry? I suggest a simple way around this problem. Rather than using words which automatically apply to humans, why don’t we add the word ‘bird’ to them. Birds can be bird-happy, bird-playing and bird-angry. There’s been 320 million years since your ancestors were their ancestors, so mental models and schemas have changed a little since our DNA stopped mixing.
This Black Guillemot looks a little bird-confused:
It’s neighbour is bird-excited:
This one is feeling bird-proud and yet bird-ignored:
And this Black Guillemot is being attacked by an Arctic Skua which is swooping in at a tremendous pace (out of shot):
It looks bird-frightened to me.
I was human-delighted to see it.