Figure 2. Regression of day of year on primary molt score for a) molting juvenile and b) molting adult Ash-throated Flycatchers (Pimm 1976). Replacement of the 10 primaries requires 50 days in juveniles and 76 days in adults. Day 180  =  29 June and day 300  =  27 October. A molt score of 0 indicates no new feather has been produced and a molt score of 10 indicates that all 10 primaries have been replaced