Early Experience Determines the Song of the Chiffchaff (Phylloscopus collybita)

Abstract

7 of 8 juvenile chiffchaff males, caught between Jul. 28 and Aug. 18 in southwest Germany, developed song in acoustic isolation which corresponded to the song of their nesting areas (Figs. 1, 2, 3). They must have learned this song institution between about 44 and 100 days of age. One captured bird with divergent syllables probably had not finished crystallizing its song at the end of the experiment.