Wonder how he does it?  Well here's some techy stuff for ya!
"I decided to go digital on this project because the complications of
 
shooting one continuous 2 1/2 minute shot.  I bought a big stack of
 
paper and scanned everything at 300 dpi. Then I drew all the character
 
sketches in photoshop and separated them into layers using vector
 
masks. After cleaning everything up, I brought them into After Effects
 
and did some rigging with Nicolas Dufresne’s inverse kinematic script
 
called Duik. If you’re an After Effects user and haven’t used Duik I
 
highly recommend playing around with it. It greatly simplifies and
 
speeds up character animation inside AE. It’s also got a bunch of
 
great animation tools aside from IK as well. Some of the characters,
 
like the birds, were parented together and rigged with more basic
 
expressions. In a couple places I animated masks over layers(see the
 
hair) or used the puppet tool(see the snake), or combined both.
 
Basically, I built each character as their own 2D compositions and
 
then placed them inside one big 3D composition where I animated the
 
camera move and added lights. It was a lot a lot of layers to render at
 
the end, but seemed simpler than splitting up the shot.
 
Big thanks to the band and Paper Garden Records for making this
 
project happen. I really enjoyed the process on this video and
 
collaborating with Pree on the specific plot points, really fleshed out
 
some of my initial ideas." - M. Sorensen