Assertion: hummingbird's foot | /r/CapableOf | loosen their grasp
Facets:
value: to swing downwards
type: PURPOSE
value: sometimes
type: TEMPORAL
Source sentences:
text: During this time, the hummingbirds cling to a branch and sit almost lifeless; sometimes their feet (which are known to be quite weak) will loosen their grasp enough to swing downwards and hummingbirds remain hanging upside down on the branch until the next morning or until they become alert when approached.