Spatial learning and memory in African mole-rats : the role of sociality and sex

Abstract

Spatial learning and memory is an important skill for the survival and fitness and may vary between the sexes depending on differences in space use. This is articularly true for animals that explore the subterranean niche as it is associated with high travelling costs. In subterranean rodents the complexity of burrow systems varies with differing degrees of sociality possibly posing stronger selective pressures regarding spatial abilities on species with more complex burrow structures. This could lead to superior abilities in spatial earning and memory in social compared to solitary subterranean species. We tested this hypothesis in two species of subterranean mole-rats, the eusocial Damaraland (Fukomys damarensis) and solitary Cape mole-rats (Georychus capensis) by comparing their ability to locate food in an artificial maze. Measurements of the time taken to the goal chamber, the number of wrong turns taken, and the average velocity at which animals travelled were used to compare performance between animals. We did not find marked sex-specific differences in either study species during the assessment of learning and memory retention. In accordance with our hypothesis significant differences between the species were apparent during both learning and memory trials with the social species exhibiting superior performances. However, in both species memory retention was generally high suggesting that the fossorial lifestyle poses a strong selective pressure on spatial abilities in subterranean mammals.