They don't urinate. So all the urea (which would normally be in urine) is passed out at the same time as their faeces. Urea is white and their faeces is brown, which is why when you look at it, their droppings are white and brown.
It contains a white substance called uric acid.
Bird droppings are white because birds don't urinate. Instead they release uric acid in their feces.
Birds do not urinate as people do. Their urine is excreted with their feces. Their feces is actually brownish-black in color and the white you see mixed in with it is the "urine", which is actually very concentrated urea, not urine itself. Also, usually the bird feces can be white with a black spot or dot, not the other way around.
feces
Birds, unlike mammals, don't produce urine. Instead they excrete nitrogenous wastes in the form of uric acid, which emerges as a white paste.
Bird excrete from their cloaca so it is a mixture of urine and faeces.
No. It is the name for bat poo.
if you like bird feces
No. It is more like the color of human feces and that of other mammals.
It can be white and this can be caused by diet changes medication etc.
No. Birds do not urinate in the way mammals do. Mammals excrete urea in their urine, which requires large amounts of water. Birds excrete uric acid instead, which requires far less water. This is the white part of bird feces.
Cryptococcosis, sarcoidosis, and histoplasmosis are the main infections.
Yes it is possible for birds to cause lung disease. It isn't right from the bird it is from the feces. Aspergillosis is a lung infection that comes from the Aspergillus fungus. Bat guano (feces) can also cause Aspergillosis. It is not a common problem but it is possible. Keep the bird(s) area clean from feces.