DO FEMALE HOUSE MICE, MUS-DOMESTICUS, REGULATE THEIR EXPOSURE TO REPRODUCTIVE PRIMING PHEROMONES

Prolonged contact with urine odours from grouped non-breeding female h ouse mice can delay puberty and inhibit oestrous cycling in female con specifics, while urine cues from males and pregnant females have the o pposite effects. The hypothesis that females regulate their exposure t o conspecific odours according to the reproductive priming effects of the cues was tested by measuring the initial (within 15 min) and longe r-term (after 24 h) behavioural responses of females towards paired ne st and feeding sites carrying different odours. Individual pre-puberta l and adult subjects from grouped housing conditions, and adults that had been isolated, were provided with a choice of clean versus female- odoured resource sites (either own group, unfamiliar group, pregnant o r non-pregnant isolate female odours), or with a choice of sites carry ing odours having opposite priming effects (male or pregnant female ve rsus grouped female odours). Results were not compatible with the hypo thesis that females responded according to the potential priming effec ts of the odours. Instead, females appeared to respond according to th e familiarity or novelty of an odour, while avoidance of odours from i solated pregnant or non-pregnant females suggested that adult females may use marks to avoid potentially defended nest sites. Adult and pre- pubertal females showed very different responses to familiar and novel stimuli, consistent with the more restricted ranges of juvenile mice within the parental territory.