Why are bird droppings white? Because they eat white chocolate? Incorrect!
Uric acid is the white part of bird waste.
In fact, the white part of bird waste is not bird droppings . The brown or green part in the middle of the white part is actually their poop. Confusing, right?
In humans, the kidneys filter nitrogenous wastes such as urea from the blood and excrete it as liquid urine.
However, kidneys in birds do not produce liquid urine. Instead, they excrete nitrogenous waste in the form of uric acid. Uric acid is the white part of bird waste .
Besides, humans have two ways to get waste out. One to remove urine released by the kidneys (urinary tract). The remaining sugar is used to remove feces released by the intestines.
But birds only have one excretory tract called the cloaca . Feces from the intestines (green or brown) and uric acid from the kidneys (white) are excreted at the same time, resulting in a mixture of white mixed with green and brown waste.
