EFFECT OF SCENT-MARKING IN DELAYING TERRITORIAL INVASION IN THE BLINDMOLE-RAT SPALAX-EHRENBERGI

The blind mole-rat (Spalax ehrenbergi) is a solitary fossorial rodent which inhabits its own tunnel system. Mole-rats are highly aggressive, and encounters between two animals in the laboratory may end in the d eath or injury of one of them. The ability to detect the presence of a nother animal's territory when tunneling may inhibit a neighbouring mo le-rat from unwanted and unexpected invasion of an adjacent tunnel sys tem as well as postpone an aggressive encounter. We aimed to determine whether mole-rats use olfaction to mark their own territorial boundar ies and to detect the territories of other mole-rats while foraging. F irst, we examined whether mole-rats scent-mark their territorial bound aries in response to the location of a neighbouring mole-rat. We found that when an intruder was introduced, the test animal almost always s hifted its latrine location to the intruder's side. Then, we used soil plugs saturated with urine plus faeces or with water to determine whe ther scent-marks influence mole-rat excavation patterns and whether th ere are differences in mole-rat reaction to a stranger's scent. Our fi ndings showed that only soil saturated with intra-specific male excret ions prolongs inhibits excavation by male intruders; soil saturated wi th water or female urine and faeces, or with inter-specific urine and faeces (Rattus norvegicus) did not have such an effect. Thus latrines may function as scent-marking stations and play a role in delaying con specifics from entering the territory. We suggest that the olfactory c hannel of communication enables mole-rats to mark their territorial bo rders with a relatively long-lasting signal, inhibiting the entry of p otential intruders (particularly males).