[realo]

Another low tech solution:

feed them occasionally on your balcony… birds are smart and they will not poo in their food plate.

Cooked pasta works well, nothing will be left when they leave.

[michaelcampbell]

Hard disagree, or our pigeons are especially daft. (To be fair, ours are wild Mourning Doves), but they crap all over the food and water receptacles we have out for a variety of birds.

[imperistan]

I was under the impression that birds have no sphincter so they can't control when they poop. Is this not true?

[geoduck14]

Some birds do, some don't.

Source: my pet duck didn't have a sphincter.

Pro tip: don't get a pet duck

[MerelyMortal]

Wouldn't it then always slowly leak out rather than become one big glop?