Assertion: woodpecker | /r/CapableOf | grip on vertical bark surfaces
Facets:
value: tightly
type: MANNER
Source sentences:
text: Zygodactyl feet--two toes in front and two in back--allow woodpeckers to grip tightly on vertical bark surfaces, and stiff tail feathers and legs form a tripod that braces against a tree as the bird hammers away.