Tamaño y estructura de los sistemas de galerías del roedor fossorial Ctenomys mendocinus en el Piedemonte de la provincia de Mendoza.

MARIA ROSI; CONA M.; PUIG, S.; FERNANDO VIDELA; VIRGILIO ROIG

Jornada; XII Jornadas Argentinas de Mastozoología; 1995

Burrow systems of the fossorial rodent Ctenomys mendocinus Philippi, 1869 werestudied in the Andean Precordillera. These burrows were linear, with laterals andbranches forked off the main tunnel. Their size and architecture did not differ betweensexes. Burrows showed a constant heading along the main tunnel, with a meandirectional angle close to 0°• Most forks of the main tunnel were originated more thanexpected at plants, indicating a change of search pattern where plants were encountered.This behaviour suggests a tactic consistent with area-restricted search. These systemswere compared with others of the same species located in a habitat with higher coverand structural complexity of vegetation, at the Mendoza Piedmont. Female burrowswere larger and male burrows more bifurcated in the Precordillera. These burrowswere more complex than those from the Piedmont, owing to the presence of secondarytunnels. The mean directional angle close to 0°, orthogonal branches and angles ofascent of laterals close to 400 were attributes shared by the systems of both habitats. C.mendocinus maintains a basic search pattern as an optimal forager, and increases thesystems size and complexity probably as an adaptive strategy to optimize the foragingefficiency and minimize the predation risk.