Effect of Scent-Marking in Delaying Territorial Invasion in the Blind Mole-Rat Spalax Ehrenbergi

Abstract 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 death or injury of one of them. The ability to detect the presence of another animal's territory when tunneling may inhibit a neighbouring mole-rat from unwanted and unexpected invasion of an adjacent tunnel system as well as postpone an aggressive encounter. We aimed to determine whether mole-rats use olfaction to mark their own territorial boundaries and to detect the territories of other mole-rats while foraging. First, we examined whether mole-rats scent-mark their territorial boundaries in response to the location of a neighbouring mole-rat. We found that when an intruder was introduced, the test animal almost always shifted its latrine location to the intruder's side. Then, we used soil plugs saturated with urine plus faeces or with water to determine whether scent-marks influence mole-rat excavation patterns and whether there are differences in mole-rat reaction to a stranger's scent. Our findings showed that only soil saturated with intra-specific male excretions prolongs inhibits excavation by male intruders; soil saturated with 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 conspecifics from entering the territory. We suggest that the olfactory channel of communication enables mole-rats to mark their territorial borders with a relatively long-lasting signal, inhibiting the entry of potential intruders (particularly males).