I think the birds and animals are about to be traumatized and are already being traumatized by much more serious and much more deadly Earth changes, at least judging from the whale beachings, mass fish die-offs, hundreds of birds falling from the sky, animals freezing to death in mid-movement. So I think 1 hour or 2 of fireworks, which are mostly concentrated in cities, not in forests, should be a lesser problem for them.
I think that the value of this symbolic "f*ck you" to the PTB is worth a bit of trauma to our 2D furry purries.