Assertion: condor's bird | /r/CapableOf | use wing
Facets:
value: as weapons
type: MANNER
value: with light, hollow bones
type: CAUSE
value: on them
type: LOCATION
value: with feathers
type: OTHER
Source sentences:
text: To do this, birds use wings with light, hollow bones and feathers on them.
text: Another "ground upwards" theory argues the evolution of flight was initially driven by competitive displays and fighting: displays required longer feathers and longer, stronger forelimbs; many modern birds use their wings as weapons, and downward blows have a similar action to that of flapping flight.