Fig. 1.

Juvenile songbirds learn song from conspecific or heterospecific tutors. a, Spectrograms of song segments from an adult zebra finch and adult long-tailed finch tutored by conspecifics (zf_ZF and lf_LF, respectively; tutor songs in Fig. 2), a Bengalese finch tutor (BF), and its adult Bengalese finch (bf_BF), zebra finch (zf_BF, brown) and long-tailed finch (lf_BF, light blue) pupils. Symbols denote BF syllable types and corresponding pupil copies, with high-magnification spectrograms of examples shown to the right. b, Both normal and cross-tutored birds learned most of their syllable repertoire from their tutor [n = 25 (zf_ZF), 11 (zf_BF), 3 (bf_BF), 10 (lf_BF), and 12 (lf_LF) birds; Tukey-Kramer post hoc tests, all P > 0.06]. c, Pupils in all groups reproduced their tutor’s syllables accurately (filled box-and-whisker plots), though zf_BF birds produced syllables that were less similar to their tutors’ than did zf_ZF, bf_BF, or lf_BF pupils [n = 192 (zf_ZF), 113 (zf_BF), 32 (bf_BF), 97 (lf_BF), and 74 (lf_LF) syllable types; ANOVAs used bird identity as a nested covariate, *P < 0.05, **P < 0.01, ***P < 0.001]. For reference, open boxplots along the top show similarity between different renditions of the same syllable type within pupils [n = 192 (zf_ZF), 113 (zf_BF), 32 (bf_BF), 97 (lf_BF), and 74 (lf_LF) syllable types], and those along the bottom show similarity between different syllable types of pupils and tutors [n = 1287 (zf_ZF), 1733 (zf_BF), 488 (bf_BF), 1210 (lf_BF), and 424 (lf_LF) comparisons]. For b and c, the measure of center is the median, box limits show the 25^th and 75^th percentiles, whiskers extend up to 1.5× the interquartile range beyond the quartiles; and circles show outliers.