Also keep an eye on the stool

Also keep an eye on the stool
Every bird owner would do well to regularly check the droppings of their birds. Changes in the bowel pattern can indicate all kinds of diseases.
Bird droppings consist of three components: feces, urine and urates, all excreted through the cloaca. In seed eaters, the feces are usually worm-shaped and dark green in color. In budgerigars that only eat pellets, it is often brown. Certain foods such as berries can temporarily change the color. If a bird does not eat for 24 hours, its feces will turn dark green to black — almost tar-like — due to the substance bilirubin.