Hawk vs Blue Jays

I saw this bluejay fighting with a hawk who just captured a rabbit. I was wondering why the bluejay kept on fighting with this hawk. The hawk just ignored him as he eats his dinner! Poor ole rabbit!

I search the Internet and read that bluejays will gang up on the hawk and yell at it. They will sit all around the hawk relatively very close. When the hawk flies from one tree to the next the blue jays will follow it as if they are trying to drive it away, they will scream at the hawk and sit at the branches above its head, to it's side and below its feet ranting and raving even after the hawk has captured its prey. The cries and shrieks of the blue jay are a warning signal to other birds that there is danger around them.

This is so amazing as I captured it and witnessed exactly what happen as per above statement I got from the net.

The one thing I could not quite understand was there was also a cardinal flying around but it was not as aggressive as the blue jay!

Wow what an amazing experience that I will never ever forget!