Short notice: There’s a new paper out in PLoS ONE (Arriaga et al., 2012) about signatures of vocal learning in mice. The main evidence is from neurological data – activation of the motor cortex during vocalisations, among others – and from behavioural experiments demonstrating sensitivity to feedback, both from others – mice modify their vocalisations when put into novel groups – and auditory feedback about their own vocalisations: the song of deafened mice deteriorates over time.
(Found through Brian Owens blogging at Nature.)
Arriaga, G., E. P. Zhou, and E. D. Jarvis (2012): Of Mice, Birds, and Men: The Mouse Ultrasonic Song System Has Some Features Similar to Humans and Song-Learning Birds. PLoS ONE 7:10: e46610. doi:10.1371/journal.pone.0046610