Song recognition memory in juvenile zebra finches: Effects of varying the number of presentations of heterospecific and conspecific songs

Seven male and three female zebra finches were exposed to 14 zebra finch (CON) and 14 starling (HET) songs during their sensitive period for song learning and then tested for their recognition memory of both the CON and HET songs in two separate memory tests. Amount of song exposure was varied by presenting individual songs either 3, 9, 27, or 81 times per day for nine consecutive days. After song exposure the birds were trained to discriminate two of the exposed, familiar songs (FAM) from two novel songs (NOV) in a go/no-go operant discrimination procedure, with FAM songs as “go” stimuli. Following discrimination training, untrained FAM and NOV songs were presented as probe songs without reinforcement. Birds responded more to FAM than NOV songs at all levels of song exposure, indicating that the songs were recognized. There were no differences in recognition memory for CON and HET song at any level of song exposure. The results suggest that selective song learning does not result from selective memorization of conspecific song.