Is this bird attacking my RC plane? Or is it just playing?

I've been working hard on my plane follow project, but do I need to? These guys do it without even thinking!
Disclaimer: Technically this is not my plane. I took the video, this was another RC pilot out at one of my favorite MAAC flying fields here in Canada. I was just lucky enough to be out at the field with my camera when it happened.
Enjoy!