Timing and body condition of dichromatic Black Redstarts during autumn migration.

Individual variation in postjuvenile molt in male Black Redstart is pronounced with about 90% of young males retaining female-like coloration ( plumage type) and about 10% acquiring adult male-like feathers ( plumage type). We examined whether autumn migration timing and body condition differed between individuals of the two plumage types. We used the data of 10,977 Black Redstarts captured during autumn at a ringing site in northern Switzerland where a protocol to record plumage types of captures has been applied since 1980.