Birds fly backwards

Since the Bug forum's "submit" button literally will not work, I'll describe my problem here. So I'm minding my own business and a few birds fly through my field of vision.

Something looked off.

I try to watch closer and it looks like the birds are flying... backwards. They move so fast it is easy to miss.

I try to catch one by pausing the game and lo and behold, this:

I am baffled and my sim is appropriately quizzical as well. I kid you not. The birds fly backwards.