Assertion: gull's tail | /r/HasProperty | brown rump
Facets:
Source sentences:
text: First-winter birds are gray-brown with a dark tail, a brown rump with dark bars, dark outer primaries and pale inner primaries, dark eyes, and a dark bill, which usually develops a paler base through the winter.
text: First-winter birds are gray-brown with a darkish tail, a brown rump with darkish bars, darkish outer primaries and pale interior primaries, darkish eyes, and a darkish bill of the American herring gull, which normally develops a paler base by means of the winter.