Generalisation of early learned tutor song preferences in female zebra finches (Taeniopygia guttata)

Song learning is a prime example for cultural transmission of a mating signal. Local or individual song variants are socially learned early in life and adults sing and prefer these songs. An unresolved issue in this context is the question of how learned preferences for specific variants generalise to songs sufficiently similar to the original model. Here we asked whether female zebra finches would generalise early learned song preferences along a similarity gradient based on syllable sharing between test and tutor songs. For each female, this gradient consisted of their tutor's (father's) song (F), two variants of unfamiliar songs edited to share 2/3 (F2/3) and 1/3 (F1/3) of syllables with father's song and an unfamiliar song (UF) not sharing any syllables with the father's song. Females' preferences were measured in a 4-way operant choice arena where birds could perch on different operant perches to trigger playbacks of the four different songs. Number and duration of perch visits were positively associated with the number of syllables that the assigned stimuli shared with fathers' songs. These results suggest that female zebra finches generalise early learned song preferences to songs sharing syllables (and/or voice characteristics) with songs learned early in life.