Assertion: great black backed gull | /r/HasProperty | pest
Facets:
value: on farmland
type: LOCATION
value: often
type: TEMPORAL
value: at airports
type: LOCATION
Source sentences:
text: Black-backed gulls are often considered pests, especially at airports (where they are a major cause of bird-strike), and on farmland, where some attack cast sheep and newborn lambs.