Odours Underground: Subterranean Rodents May Not Forage "Blindly"

Subterranean rodents were thought to forage underground for edible roots and bulbs without the benefit of any sensory cues. Subterranean rodents representing four genera from three families (East-Mediterranean Spalax, African Cryptomys and Heterocephalus, and South American Spalacopus), tested in T-mazes filled with soil in which edible plants either had or had not been growing, used odours to discriminate between the soils and chose to dig in the soil containing odorous substances (kairomones) released from roots of growing plants. Such discriminations could enable them to orient their digging toward food sources in the field and thus to improve their foraging efficiency. Spalax blind mole-rats also discriminated between the odours from soil in which edible as opposed to poisonous plants had been growing. These species evolved independently on three continents; thus their abilities probably are characteristic of subterranean rodents in general.