Assertion: penguin's presence | /r/HasProperty | inconsistent
Facets:
Source sentences:
text: The afterfeathers are downy plumes that attach directly to the main feathers and were once believed to account for the bird's ability to conserve heat when under water; the plumules are small down feathers that attach directly to the skin, and are much more dense in penguins than other birds; lastly the filoplumes are small (less than 1 cm long) naked shafts that end in a splay of fibers— filoplumes were believed to give flying birds a sense of where their plumage was and whether or not it needed preening, so their presence in penguins may seem inconsistent, but penguins also preen extensively.