Diet of the vizcacha Lagostomus maxim us (Rodentia, Chinchillidae), habitat preferences and food availability in Northern Patagonia, Argentina

PUIG, S.; FERNANDO VIDELA; MONICA CONA; MONGE S

MAMMALIA

WALTER DE GRUYTER & CO

Lugar: Berlin; Año: 1998

0025-1461

Composition and seasonal changes in the diet of the vizcacha (plaips vizcacha)were determined in four habitats of La Payunia Protected Area, through faecal analyses and inrelation to food availability. Space use of vizcachas in the spatial heterogeneity (a mosaic ofplains and rocky elevations) was evaluated by means of vizcacheras (burrows) localization. Dietincluded 29 genera of plants, mostly grasses and forbs, Poa and Panicum being main dietary ele-ments. Vizcacha did not appear as a generalist herbivore, since grasses constituted 94 % of thediet, and only three grasses were used frequently. A high selectivity ocurred in habitats and sea-sons with low plant diversity. This fact does not agree with the optimal foraging theory, and mayreflect a forced selectivity induced by the low quality of available resources for vizcachas in LaPayunia. Scarcity of forbs could explain this low nutritional resources quality. Rocky elevations,the habitat of Lagidium viscacia, was not inhabited nor visited for feeding by vizcachas,although 26 % of vizcacheras were found at the foot of these elevations. Dietary preferences andantipredation strategy would explain why vizcacha restricted its habitat to plains.