SIZE AND STRUCTURE OF BURROW SYSTEMS OF THE FOSSORIAL RODENT CTENOMYSMENDOCINUS IN THE PIEDMONT OF MENDOZA PROVINCE, ARGENTINA

The structure and size of burrow systems of Ctenomys mendocinus were a nalysed in the present study. These burrows showed a linear pattern, w ith a main axis from which branches and laterals forked of Burrow syst ems of males were larger than those of females, with a longer main tun nel and greater number of branches. Lengthening of the main tunnel was achieved by adding new segments rather than by excavating longer segm ents. Both male and female burrows showed the same geometric configura tion. There were no differences in the percentages estimated for main tunnel, branches and laterals. The angular variables (directional angl e, branch angle and angle of ascent of laterals) did not show any diff erences between both sexes either. Burrows showed a constant heading a long their path with mean directional angles close to 0 degrees, even though in most systems left- and right-ward deviations from the main t unnel followed a random sequence. Branches originated at right angles to the main tunnel. C. mendocinus appears to minimize the energy cost of burrowing by increasing the angle of ascent of the lateral instead of its length as the main tunnel grows deeper. Home range, perimeter, and linearity were significantly higher in males.