Burrow architecture and burrowing dynamics of the endangered Namaqua dune mole rat (Bathyergus janetta) (Rodentia: Bathyergidae)


N. C. Bennett, Department of Zoology & Entomology, Mammal Research Institute, University of Pretoria, Pretoria 0002, South Africa. Tel: +27(12) 420; Fax: +27(12) 420
Email: ncbennett@zoology.up.ac.za


The Namaqua dune mole rat Bathyergus janetta is a solitary subterranean rodent that occurs in the arid and sandy regions of Namaqualand. The predictable winter rainfall and high diversity of geophytes, the predominant food resource, enables the mole rat to survive in this extreme environment. Burrowing and burrow system configuration were measured by observing mound production and the excavation of six mole rat burrow systems. A typical burrow system comprises nest chambers, food stores, defecation sites and bolt holes, which serve as a place of retreat when the animal is alarmed or threatened. Males tend to have linear-shaped burrow systems, whereas the burrow systems of females are more reticulate. The linear nature of the male burrow system probably increases the home range used to search for potential mates. Burrow systems undergo constant excavation and re-excavation within the home range. The average burrow length ranges from 71.2 to 165 m with a mean home range of 805.8±375.5 m2.