Assertion: pigeon's bird | /r/CapableOf | tip the head
Facets:
value: to swallow
type: PURPOSE
Source sentences:
text: Pigeons also are distinctive in their unusual manner of drinking, in which water is sucked in as a continuous draft, the process being assisted by muscular contractions of the esophagus , whereas other birds take a sip of water and then tip back the head to swallow.