Assertion: mallard's speculum | /r/HasProperty | wing patch
Facets:
Source sentences:
text: Both male and females have a blue speculum (wing patch) bordered with white on each wing.
text: However, the mallard is the only one duck with blue speculum (wing patches) that are bordered on both sides by white.
text: However, the body is darker overall and there are no white borders on blue speculum (wing patch).