Who is watching who?

I blipped this last summer but didn't spot the lens in the belly button.

I wonder who is being observed or counted?

A buzzard flew over with what looked like nest building materials, until the nest building materials squirmed, ergo the nest must be built of snakes. It must be warm if snakes are already appearing. We also watched the courtship of two Rooks. He handed, or beaked, her a very nice pebble. Must bear that in mind next time I upset Mrs Booty.