Ack, didn't think of this til after hitting send... On Tue, 9 Apr 2013, Richard W. Travsky wrote:
... http://m.techradar.com/news/video/software/applications/the-making-of-pixars-up-603600 ... As if the balloons weren't enough, the bird character Kevin posed another set of challenges that were no less complex. The first challenge was to give the bird's iridescent feathers a soft, fluffy appearance.
Short youtube video of the bird. Make sure you select HD quality. Gives some idea of what things could look like. https://www.youtube.com/watch?v=eeJ38HE8Q7U Kevin (the bird) from Pixars Up