Assertion: hummingbird's flight | /r/HasProperty | efficient
Facets:
Source sentences:
text: This type of flight control is more closely associated with insects such as dragonflies than with birds and is a unique adaptation the hummingbird has harnessed for efficient flight.
text: They do so regularly, and, as reported by BBC Nature News, research has found that hummingbirds' "backward flight is efficient.