Keywords: outdoor bird animal "That's the theory, that retained streaking after the complete preformative molt in these (Botteri's, Cassin's, Bachman's) indicates a first-year bird (SY in spring). I'd say the rather duller and paler average plumage to the streaked bird(s) compared with the adults favors this as well. Note these are formative feathers retaining juvenal characters (e.g., that the hormones that produce streaks in juvenal feathers had not entirely subsided during the first molt) rather than retained juvenal feathers." Peter Pyle "That's the theory, that retained streaking after the complete preformative molt in these (Botteri's, Cassin's, Bachman's) indicates a first-year bird (SY in spring). I'd say the rather duller and paler average plumage to the streaked bird(s) compared with the adults favors this as well. Note these are formative feathers retaining juvenal characters (e.g., that the hormones that produce streaks in juvenal feathers had not entirely subsided during the first molt) rather than retained juvenal feathers." Peter Pyle |