Wing lengths of Clamorous Reed Warblers Acrocephalus stentoreus in Israel

Wing length measurements taken from first-year, pre- and post-moulting (annual, complete) Clamorous Reed Warblers were recorded at a site in northern Israel. The resulting data set was examined using a time-series of residuals (CUSUM). Results from this analysis can explain the reported heterogeneity found in a comparable data set by Merom et al. (1999). Further observations made in their paper are rebutted: (1) an implied assumption that Reed Warbler (Acrocephalus scirpaceus) spring migration in Israel ends by 1 May is contrary to other publications; (2) the late autumn occurence in N Israel of longer-winged 1^st cal. yr. Reed Warblers, unconvincingly explained as either delayed migration by larger individuals or post fledging feather growth, is most likely due to birds from different provenances origins moving at different seasons; (3) growth during adulthood in Reed Warbler is not a new discovery, though presented as such.