Assertion: purple martin | /r/HasProperty | dependent on man-made housing
Facets:
value: to nest
type: PURPOSE
value: a situation that has existed
type: OTHER
Source sentences:
text: Purple martins are dependent on man-made housing to nest, a situation that has existed for hundreds of years when local Native Americans first hollowed out actual gourds (instead of the artificial ones used most often today) and hung them on trees.