Large-Scale Surveillance of Captive Naked Mole-Rat Colonies Shows Caste Differences in Space Utilization

Authors

Michael Kress, CUNY College of Staten IslandFollow
Edward F. Meehan, CUNY College of Staten IslandFollow
Dan McCloskey, CUNY College of Staten IslandFollow

Document Type

Working Paper

Publication Date

2017

Abstract

African naked mole-rats are eusocial mammals that provide unique opportunity to study complex mammalian social behavior and large-group dynamics in a controlled vivarium setting. Previous reports of captive and wild naked mole-rats have identified a division of labor among non-reproductive colony members along a size polyethism, with large animals specializing in defense behaviors, and small animals performing foraging, nest building, and caretaking functions. This study utilized radio frequency identification (RFID) and advanced computational approaches to monitor the activity patterns and place preferences of all members in two naked mole-rat colonies (N = 36 and 37 animals) for a period of 26 days. Results demonstrated colony differences in- and therefore suggested social regulation of- patterns of colony behavior. Mapped onto different colony rhythms were more universal rules for space preferences depending upon the size and role of the individual: the Queen/Male breeders and the large workers spent almost all of their time in and around (colony-defined) nest chamber, while the smaller workers were more likely to visit the (experimenter-defined) feeding chamber and other areas of the semi-natural habitat. Earlier claims of “lazy” large colony members, were not confirmed, as there were no differences in activity or measures of stationary hours between castes of workers. Animals in the breeder castes demonstrated among the fewest stationary hours of all colony members, with a high concentration of activity around the nest chamber. These findings provide a unique insight to patterns of activity that would be difficult to identify visually and allow for a better understanding of individual contributions to naked mole-rat colony behavior.