How? Warning: This Post Contains Bird Poop

I have a very simple question. It shouldn't be that difficult to figure out, but my husband and I have been scratching our heads about this for a few days.

And my apologies if this is TMI or not appropriate (I did a quick search on agent blogs, but none of them have mentioned if bird poop is an acceptable blogging topic for aspiring authors) but I am not trying to be gross. I just honestly want to know.

How did bird poop end up on the side of my apartment wall? It's right between the door and the window. Here's a picture for reference:

You can see the bird's little gift to us in the middle. And before you run to the comments and tell me that all animals have to poop, let me give you some more perspective:

That's the hallway. There is several feet of walkway, a railing, and a large overhang past the balcony. My husband and I stood outside and looked around the apartment, trying to figure out the exact trajectory that would cause poop to land on the inside of our apartment balcony, against the wall. 

We have no answers. What you see to the left is a large tree. It's not like a bird could fly towards that exact spot and the wind just carried it's donation the rest of the way. There's a monstrously large tree in the way. The overhang should prevent the bird's butt from getting anywhere near the railing, much less three feet inside along our wall.

I keep trying to line up the trajectory, but no line I draw through the spot in question and the outside matches up. Then again, I am not a physics major. 

But still. Did the bird do a barrel roll through the hallway? There's nothing for them to perch on inside the walkway, so it didn't happen while they were hanging out. My husband's theory is during that bad windstorm/tornado watch we had a few days ago the bird got scared and the wind carried it. But I am not convinced.

Did I piss the birds off somehow? Has my apartment been marked for death? Am I in the middle of some sort of bird holy war? Is this their way of telling me I need "protection" and should donate in the form of bird seed and bread?

I am pretty sure it was the cardinals. There's two of them that like to sit on the tree outside and look smug. I mentioned how the cardinals always look smug on Twitter (Twitter...as in birds...coincidence? I think not.) and the next day...bird poop on the side of my apartment.

I don't know. Perhaps those of you with a science background can work out the right angle for me. Because at the moment, I am going with blaming the cardinals.

And yes, I cleaned it up. Who knows what that's bird-code for?