Upper-Shen Mountain or Shangshen is a rugged, rocky peak with no vegetation on it, but there are hazelnut groves at its base. There, Danghu birds can be seen flying from branch to branch. A danghu looks like a pheasant, but it flies using its hypertrophied whiskers and throat feathers. Consuming a danghu protects from and cures myopia. Guo Pu extolled the virtues of the danghu, using it as a metaphor for the economical mindset of Daoism as it makes do with what it has.
Mathieu suggests that this bird is the masked Japanese grosbeak (Eophona personata), which is nonetheless unwhiskered and unpheasantlike.
Mathieu, R. (1983) Étude sur la mythologie et l’ethnologie de la Chine ancienne. Collège de France, Paris.
Strassberg, R. E. (2002) A Chinese Bestiary: Strange Creatures from the Guideways Through Mountains and Seas. University of California Press.