Science fact: The white stuff in bird droppings is urine; the black stuff in the middle is the feces.
I had a biology prof in college who was obsessed with the biology of elimination. He taught that human feces is brown because of the iron in the dead red blood cells filtered by the spleen (don’t laugh!!) but a similar process in birds produces the color of their eggshells. (Why eggshells come in so many colors he did not explain.)
Science fact: The white stuff in bird droppings is urine; the black stuff in the middle is the feces.
I had a biology prof in college who was obsessed with the biology of elimination. He taught that human feces is brown because of the iron in the dead red blood cells filtered by the spleen (don’t laugh!!) but a similar process in birds produces the color of their eggshells. (Why eggshells come in so many colors he did not explain.)