At least two pheromones exist in female house mouse urine that elicit
70-kHz ultrasonic mating vocalizations from males: (1) a potent albeit
ephemeral pheromone found in freshly voided urine which disappears wi
thin 15-18 h and (2) a more persistent, but less potent pheromone that
remains for at least 30 days. Three experiments examined whether male
responsiveness to the ephemeral pheromone and its loss in aged urine
were due to volatility or oxidation. Experiment 1 demonstrated that bo
th sexually experienced and inexperienced males must physically contac
t fresh urine before vocalizing. Experiment 2 indicated that storing f
reshly voided urine in an air-tight syringe does not attenuate the los
s of the ephemeral pheromone. Experiment 3 demonstrated that the loss
of activity of the ephemeral pheromone can be prevented with either be
ta-mercaptoethanol or dithiotreitol. Thus, the ephemeral pheromone is
non-volatile and appears to be degraded by oxidation. (C) 1995 The Ass
ociation for the Study of Animal Behaviour