What an interesting movie this could have been! But instead of teaching us about it, they presented lots of pretty pictures and not much substance. 5 minutes will pass with no dialogue and the camera simply panning in or out. The pictures are beautiful, so if that's your thing, you'll love it. If you want to learn anything about this phenomenon or about habitat or species destruction or adaptation to how humans of changed our planet and environment, then you'll have to look elsewhere. It was a real shame since there is so much to say and show about this topic and it could have been a very edifying experience.