Assertion: black vulture's feather | /r/HasProperty | the first
Facets:
Source sentences:
text: Jack Eitniear of the Center for the Study of Tropical Birds in San Antonio, Texas reviewed the plumage of birds in captivity of various ages and found that ventral feathers were the first to begin turning white from two years of age onwards, followed by wing feathers, until the full adult plumage was achieved.