"But what about tertial replacement? As my post title suggests, perhaps we need to revisit this feather group: Do 1st cycle Ring-billeds replace their tertials in the first plumage cycle? If so, through what molt? Traditionally, the literature has held that 1st cycle Ring-billeds rarely, if ever, replace tertials. About two years ago, I began to suspect differently as I was finding more and more individuals with juvenile primaries that showed one or two, and sometimes all of their tertials renewed." - John (bird whisperer)