What bird product was an important fertilizer in the 19th century?
Bat poo Seal shit Bat droppings Birdshit Bat guano Seabird shit Bat shit Bat Shit Batshit Bat poop Guano Phosphate rock island Bird shit Bat paste
phosphate rock island guano bat poop bat shit bird shit bat droppings bat paste birdshit bat guano seal shit seabird shit bat poo batshit
guano
WikipediaEntity
Guano