Demography and microhabitat use of the wild guinea pig (Cavia aperea Erxleben 1777) in freshwater marshes of Spartina densiflora (Brong.) in Argentina

BONAVENTURA, S. M.; VERONICA ANDREA PANCOTTO; MADANES, N.; VICARI, R.

Acta Zoologica Sinica

Elselvier

Año: 2003 vol. 49 p. 20 - 31

We studied abundance, reproduction and microhabitat use of the wild guinea pig (WGP), Cavia aperea, and its influence on vegetation and sigmodontine rodents during the fall-winter period in freshwater Spartina densiflora marshes . WGP preferred microhabitats with high S. densiflora cover. Reproductive individuals (= adults) mainly used patches dominated by short grasses, while juveniles used patches with forbs. These results suggest that microhabitat use in the WPG is influenced by predation risk (availability of safe foraging sites and refuges) and type of food. In freshwater marshes, WGP abundance, reproduction, body weight and microhabitat use exhibited no seasonal variations, and their herbivory and runway construction activities had no negative effect on vegetation structure and sigmodontine rodents. Results from a comparison between WGP populations living in freshwater habitats (moderate seasonality) vs grasslands and roadsides (strong seasonality), suggest that the population dynamics of the WGP, as well as the impact of the WGP population on vegetation and on coexisting rodent communities, are influenced by the availability of plant cover during winter