They remind me of seagulls, maybe... very elegant seagulls. What I like about this picture is that the two creatures don't seem to recognize each other- perhaps the notion that they can only express themselves through hats and not their faces?
Very nice! I like the texture, and hats with question marks, and the little details of the strings holding their masks.
That said, my first thought on seeing this particular image was of those concrete goose lawn sculptures that some strange people put clothes on. But I expect that this is simply cos my aunt just told to me a story about somebody doing this.