It is maybe not easy to see but there is a raven inside the cage hidden behind the loose raven. The legend say that the Tower of London will not fall as long as there are ravens at the Tower. On a sign I read that there are ravens born at the Tower but also rescues at the Tower. I don´t know if the ravens in the cages may be rescues or young ones and the loose ravens older ones born here or trusted not to run away even though the ravens have clipped wings. On Wikpedia there is more information about the ravens at the Tower of London. More critter pictures on Camera Critters and more bird pictures on The BIRD D’Pot .