Length of the growing replacement feather in relation to time since removal.

Linear models of the residuals of replacement R4 length relative to original R4 length on time since original feather removal (LengthRe in the text), on date and breeding stage for either sex separately or for the two sexes pooled. The statistics for the intercept and the first-order term for females are obtained from a model excluding the non-significant second-order polynomial term (in parentheses). Only re-growing feathers measured less than 40 days after plucking are considered (see Fig. 2).