Air resistance would make flight harder, though, not easier, wouldn’t it…?

As I understand it wings work by Bernoulli’s principle, which is an air pressure / conservation of energy thing, so it should still work in a frictionless atmosphere…

Then again, we’re talking chickens here (and spherical ones at that), which aren’t particularly renowned for their aerodynamics and wing efficiency, so maybe they would need to be able to push on the air to generate lift…