Bird droppings invalidating location for prayer?

Question

One may not pray near feces or other sources of biological waste and decay that give a foul odor (see the article for several opinions on when/how it applies). Does this include bird droppings?

I've never smelled a foul odor from them, but I imagine that if someone kept dozens of birds together in a house and didn't clean the house, that the build-up of droppings would smell, meaning that there is some foul smell. And it is biological waste.

Does this mean that it falls into the same category as cow manure for purposes of the Halachah?

Answer 1

At the end of Shulchan Aruch Orach Chaim 79:4, the Mechaber writes with regards to a a bird's waste that one does not have to distance oneself from it if it doesn't stink, but if it does stink it has the same law as the waste of a person.

The Mishna Berura explains (S"K 22) that unless one knows for a fact the waste stinks he can assume it doesn't. He also (S"K 23) Defines stink as being so bad that a person is pained from it.

(Also see the S"K 24 regarding the Magen Avraham's leniency regarding the stink of birds' - and regular animals' - waste)

Answer 2

The prohibition to pray near feces is only for feces that either smells bad, even if it doesn't come from a species whose poop normally smells bad; or if it comes from a species whose poop normally smells bad, even if it doesn't smell bad.

You aren't allowed to pray near the poop of turkeys and you're not allowed to pray near a chicken coop, but I think you're allowed to pray near the poop of chickens, since — as you mentioned — it usually doesn't smell bad.

Source: Shulchan Aruch 79:5-8 and MB there