Assessing chemosensory perception in subterranean mole rats: different responses to smelling versus touching odorous stimuli

A new bioassay was developed to enable quantitative and qualitative assessment of subterranean mammals' responses to chemosensory stimuli. Mole rats of theSpalax ehrenbergisuperspecies of Israel responded differently to the odours of conspecific and heterospecific urine depending upon whether they had previous experience with touching the urine with their noses. Mole rats were initially indifferent or slightly attracted to the odour of both conspecific and heterospecific same-sex urine although their behaviour indicated that they could smell it. When animals were given the opportunity to touch the stimulus with their noses, they tended to avoid both types of urine. When exposed to the odour alone, in a separate experiment that followed the touch experiment, the avoidance tendency remained. These results suggest that the animal learns about the odour of the urine through nasal contact with it. Mole rats were indifferent to smelling and touching their own urine and urine of a novel non-competitor rodent (guinea pig,Cavia porcellus) and avoided the urine of a potential predator (marbled polecat,Vormela peregusna) without the necessity of touching it.