Explosive vocal activity for attracting human attention is related to domestication in silver fox

Domestication affects behavioral and vocal responses, involved in communication with humans; in particular, those that attract human attention. In this study, we found that silver foxes of Tame strain, experimentally domesticated for a few tenses of generation, displayed bursts of vocal activity during the first minute after appearance of an unfamiliar human, that faded quickly during the remaining time of the test, when the experimenter stayed passively before the cage. Distinctively, foxes of Aggressive strain, artificially selected for tenses of generation for aggressive behavior toward humans, and the control group of Unselected for behavior silver foxes kept steady levels of vocal activity for the duration of the tests. We found also that Aggressive foxes vocalized for a larger proportion of time than Unselected foxes for all 5 min of the test. We discuss the obtained data in relation to proposal effects of domestication on mechanisms directed to involving people into human-animal interactions and structural similarity between human laughter and vocalization of Tame foxes.