Parrots and parakeets apparently eat unripe fruit. There is less competition for the food, but it also does not give them all the minerals that they need. Every morning, thousands of them show up at various spots like this one to lick the rock for those minerals. There can, of course, be some "discussion" as to who gets the good spots. The parrot at the lower left is not actually falling: he spent most of the time happily hanging upside down to do his licking.