I agree the hole is too small for a Robin, BUT I have this Robin sitting on top of the BB house chirping away as if looking for a mate. It’s so weird since I’ve never had Robins land there and perform this way before. He/she almost reminds me of a house wren in behavior.
As for the cam, I might be interested depending on the cost. Any suggestions about that or the latest insanity. (Still can’t get the picture of that magnificent dead male out of my head )