Sometimes, it's like the bird is posing for you. "Here are all my identifying features! Quick take a picture". Sometimes it's still not enough. Look at these examples:
Proof once and for all, if any was needed, that this is not a Shag.
Compare it to this:
Is it greater or is it lesser? I just cant tell. I'd incline towards lesser, but I'm buggered if I know why.
Still, that's what blogs are for. Put me out of my misery.