First I should say that that trying to figure out speed based on fps is probably going to be a waste of time since you don't know distance from camera nor frames per second. But that said, I believe it to be a bat. We get a lot of them flying around here between dusk and dawn, and I think that one is just motion blur, they're pretty quick. That's the second time I've caught such a thing on camera, and they both looked very similar.
