I'm so blown away by the clarity of speech! After hearing him talk like that, hearing the normal bird noises almost sounds strange, like a human mimicking a bird, or like he's gotten impatient and wants us to understand his native language.
If you haven't watched it already, you should check out 'Dancing With The Birds' on Netflix. Maybe I'm biased being a huge bird lover, but man that movie left me in awe. This scene in particular...
https://youtu.be/Eg0iSIHIK34
You might enjoy the superb lyre bird imitating sounds as mind boggling as a chainsaw--and when I say imitate, I mean I couldn't have distinguished the lyre bird sound from a real chainsaw. It's really mind-boggling to me.
Many compress quite a lot before uploading. For gaming for example, I noticed significant improvement if I uploaded the 100Mbps raw data from Shadowplay compared to say a 25Mbps intermediate version.
I also think the depth of field is helping a lot. By blurring out the background the bits can be spent encoding the details of the plumage.