Maternal behavior influences vocal practice and learning processes in the greater sac-winged bat

Learning, particularly vocal learning, is often a social process. In human
infants, it is well-established that social interactions influence speech
acquisition and are hypothesized to modulate attentiveness and sensory
processes, thereby affecting the speech-learning process. However, our
understanding of how social interactions shape vocal ontogenetic processes
in non-human mammals, particularly those which vocally learn, remains
limited. In the bat Saccopteryx bilineata, pups acquire the adult vocal
repertoire through a distinctive babbling behavior that shows interesting
similarities to human infant babbling. While babbling encompasses many
different syllable types, it is particularly noteworthy that pups learn
song syllables by imitating adult singing males. The pups’ social
environment involves frequent interactions with their mothers, whereas
adult males mainly serve as the primary source of acoustic input. We
monitored the vocal ontogeny of 19 wild pups of two populations,
investigating whether their social environment (i.e. maternal influence,
number of singing tutors) influenced three aspects of babbling: the amount
of vocal practice, the pups’ final syllable repertoire size and the
production of the syllable types acquired through vocal learning. The
results demonstrate that maternal behavioral displays significantly
influence the amount of vocal practice, the presence and versatility of
song syllable types in babbling and the percentage of mature song
syllables. Our findings show that maternal feedback plays a significant
role in the vocal ontogeny and learning processes of S. bilineata, thus
enhancing our understanding of the relationship between social feedback
and vocal development in mammalian vocal learners. The shared files
contain the raw data used for our analyses.