In England, pigeon poop is property of the Crown.

In England, pigeon poop is property of the Crown.

In the 18th Century, King George I of England decreed all pigeon droppings to be property of the Crown. He even put guards at sites where the birds perched to enforce his edict. He was no birdbrain. There was a practical reason for his order: Pigeon manure was used in making gunpowder.

Pigeon guano (droppings) can be very dangerous. Ornithosis, Listeria, E-coli and other nasty pathogens can be passed through droppings and by the birds themselves. When dry, the droppings can become airborne leading to respiratory complaints such as psittacosis, and the cryptococcus fungus.

Pigeon poop, or guano, is nitrogen rich, making it an excellent source of fertilizer. The use of pigeon guano as fertilizer continued throughout history up until the development of agribusiness that resulted in cheaper more efficient means of fertilizer.

The pigeon's excretion system is not the same as that of a mammal. The food passes through the digestive system and empties from the rectum into the cloaca. This literally means “cesspool” and is the “emptying place” for both the digestive and the urogenital system in pigeons.