Who ever made this video, certainly did not expect to film something like this. It was filmed somewhere in Netherlands and in the beginning you might think that it is nothing interesting, it looks like an every other ordinary tree, but if you wait a little while you will see something amazing.
There is not anything weird when you see a flock of birds on the branches of the trees, like it is not anything extraordinary to see them flying away simultaneously. But , then imagine so many birds on one tree, than when they fly away you see something entirely different, or in this case you can see that the tree does not look even close to what you can see in the beginning of the video. At one point it reminded me of the movie by Alfred Hitchcock.