Assertion: penguin's bird | /r/CapableOf | moult their feathers
Facets:
Source sentences:
text: Unlike flying birds, which moult and replace their feathers slowly so they can remain airborne, penguins moult all at once over a period of 2 – 5 weeks during the summer.
text: Unlike flying birds, which moult and replace their feathers gradually so that they can continue to fly, penguins moult all of their feathers at once.