Assertion: nuthatch's cavity | /r/HasProperty | natural
Facets:
Source sentences:
text: Rather than build its own nests, the Eurasian Nuthatch seeks a vacated woodpecker’s nest or a natural cavity in a tree in which to build its cup-shaped nest.
text: The cavities may be natural, or the nuthatch may excavate it in soft, rotted wood.
text: The White-breasted Nuthatch generally nests in natural cavities or old woodpecker holes.