Assertion: california condor's head | /r/HasProperty | cleaned
Facets:
value: by rubbing them
type: MANNER
Source sentences:
text: plumage is carefully preened and kept well arranged; the bare head and neck are cleaned after feeding – by rubbing them on grass, rocks, or branches.
text: California condors also spend much of their time grooming; plumage is carefully preened and kept well arranged and the bare head and neck are cleaned after feeding.