Assertion: swan's size | /r/HasProperty | harder to gauge
Facets:
Source sentences:
text: Distinguishing tundra and trumpeter swans from a distance (when size is harder to gauge) can be challenging without direct comparison but it is possible thanks to the trumpeter's obviously longer neck (the great length of which is apparent even when the swan is not standing or swimming upright) and larger, wedge-shaped bill as compared to the tundra swan.
text: Distinguishing Tundra and Trumpeter Swans from a distance (when size is harder to gauge) is quite challenging, and can often be done only with experience and knowledge of structural details.