Do bird droppings and urine invalidate prayer or ablution? Is it permissible to pray in clothes that have been stained by bird droppings or urine, if one did not notice it?

The urine and droppings of animals whose meat is permissible to eat, whether birds or beasts, are considered pure by the majority of jurists due to widespread affliction. However, the Shafi'is and some Hanbalis consider them impure, but they pardon it due to hardship. Wudu is not invalidated by it whatsoever.