Bird strike, and I am not a pilot

I was sitting at my desk, minding my own business when a bird decided to go one-on-one with the window pane at my office. Result: Window 1, bird 0. Luckily it didn't come back for round 2.

I still can't figure out why the bird just whacked into the window. Was it confused? Was it chasing after it's dinner? Was it sick? Was it a suicide dive bomber?

Anyway, it did leave a mark on the window: