Lovely design.
I think the designer changed colors from the skein as desired rather than working thru the skein as the colors changed within it.
Doing that as well to get different colors for various sections.

Fashioned a beak and set of legs / claws from yarn.

Don’t know how the designer used 2.0 and 2.5 mm hooks with an aran yarn. That’s some firm gauge crocheting.