However, here are some options you could use depending on the context:
General terms:
* Covering: This is a broad term that encompasses all three.
* Growth: This focuses on the biological aspect of these features.
* Pelage: This specifically refers to the fur of animals, but can be extended to feathers and hair in a metaphorical sense.
More specific terms:
* Fur itself can be used as a collective noun, like "a thick fur of the fox."
* Plumage is the collective term for feathers.
* Mane refers to the long hair on the neck of certain animals, and coat can be used for hair in general.
Ultimately, the best term depends on the context and the specific nuance you're trying to convey.