Assertion: narwhal | /r/CapableOf | use whistle
Facets:
value: at the surface
type: LOCATION
Source sentences:
text: Narwhals and most other toothed whales navigate and hunt using clicks, knocks, and whistles.
text: Narwhals communicate using clicks, squeals and whistles.
text: One such fact is that narwhals communicate using clicks, squeals and whistles.
text: At the surface, the narwhals instead used whistles and trumpetlike calls to communicate.