In my city we have legends about a bearded vulture that was living in the city and was soo friendly that people could pet him like a stray dog.When it died shot by a german soldier that got skared by the vulture ,houndreds of kids and people took the vulture and they got to burry him in the most expensive cemetary.2 books were written about this bird,one brand of beer was named ,,Vultur,, and one pub named after him,Vulturul Ilie.
Now to the subject,these vultures eat only bones and theire the only birds in the world that do this.Since they dont eat flesh they are peacefull and make great pets.They let the crows and otther birds to eat the flesh and then they go only for the dry bones wich they take into the air and drop them on stones from above if the bones are too big to swallow.Altough its the most peacefull possible raptor bird it did killed a human in recorded history.A bearded vulture killed Aeschillus,the father of the greek tragedy ,when the vulture dropped a dead tortoise in Aeschillus head ,because aeschillus was bald and the vulture thoght his bald head was a stone.So i immagined that this vulture poo should contain lots of Phosphorus because the bones are made of calcium Phosphate.
This vulture specie is now extinct in my country or close to be extinct and in fact Vulturul Ilie was the last one left and didnt find a pair to mate wich led him to live in the city among the people that wiped out its specie because somme politician said to shot them all for a wrong reason.But instead of vulture poo thats high in P im thinking to fed bones to my dog and colect the white droppings wich should make a verry high in P fertiliser.I have only a few trees that need P fertiliser and a little goes a long way.