What is name for excretory organ of a bird?

The excretory organ of a bird is called the kidney. Birds have two kidneys, which are located in the abdominal cavity, near the backbone. Kidneys are responsible for regulating the balance of fluids and electrolytes in the body, and for removing nitrogenous waste products from the blood. In birds, the kidneys produce urine, which is then transported to the cloaca, where it is mixed with feces and eventually expelled.