Naked mole-rats recruit colony mates to food sources

Abstract

Naked mole-rats, Heterocephalus glaber, are eusocial, subterranean rodents that inhabit arid regions of northeastern Africa. They feed on bulbs and tubers that are patchily distributed. Nests are often located far from the nearest food source through a labyrinth of tunnels. Two captive colonies were studied to determine whether successful foragers recruit colony mates and, if so, how. Individuals that found a new food source typically gave a special vocalization on their way back to the nest and waved the food around once they got there. Colony mates preferentially visited the site where the initial forager had obtained food, often bypassing alternative sites containing the same type of food. Recruits preferred to use tunnels that had been traversed by the 'scout' rather than an alternative pathway to the same food, regardless of whether they had to turn in the same or the opposite direction from that of the scout to enter the previously used pathway. Recruits preferred tunnels that the scout had recently used over tunnels that were recently traversed by another colony male carrying the same type of food. When tunnels traversed by the scout were replaced with clean substitutes or with tunnels that were recently traversed by another colony mate carrying the same type of food, recruits showed no pathway preferences. Results indicate that naked mole-rats follow each other's (odour) trails to food. There are intriguing parallels between the foraging recruitment system of H. glaber and those of other social vertebrates and insects.