Laterality in naked mole-rats (Heterocephalus glaber)

Lateralization, or the preferential use of one body side, limb or eye over the other, has been suggested to impact learning and decision-making processes critical for survival and is widespread in various animal species. Naked mole-rats (Heterocephalus glaber) are cooperatively breeding subterranean rodents with excellent spatial navigation skills, necessary for living in complex underground burrows. Here, we investigated i) whether naked mole-rats display laterality, and if so, whether ii) laterality is affected by their age, sex, or group membership. We tested 69 captive individuals from five families, using a T-maze apparatus that was systematically rotated across 24 trials per individual to mitigate any potential environmental effects. We measured the Initial Turn made and the arm chosen (i.e. Arm Turn), calculated Z-scores, Laterality and Absolute Laterality Index, and constructed linear regression models. We expected to find a directional laterality bias in individuals and a stronger laterality bias in older ones, but no sex or group effects. While most individuals displayed a right-turning preference in their initial turn, they were ambilateral when choosing between the two side chambers. Furthermore, there were no age, sex, or group effects on the direction or strength of laterality in the Initial Turn, nor on the direction or strength of laterality in the Arm Turn. Further investigation using other modified and ecologically relevant experimental designs is warranted to understand the underlying mechanisms and ecological implications of laterality and turning bias in subterranean rodent species.