Habitat use and diet in sympatric species of rodents of the low Parana delta, Argentina

SUAREZ O.V.; BONAVENTURA S.M

MAMMALIA

Museum National d´Historie Naturelle

Lugar: Paris- Francia; Año: 2001 vol. 65 p. 167 - 176

0025-1461

Plant cover availabailty has been mentioned as one of the most importtant resources determining cricetid habitat use. In this paper we described the effect of variations in the principal dietary items on the use of low and up habitats by Oxymicterus rutilans, Akodon azarae, Scapteromys tumidus and Olygoryzomys delticola in the low delta from Buenos Aires. Our results show that A. azarae feed mainly on invertebrates an to a lesser degree on plant remains. Invertebrates are also the principal item in S. tumidus and O. rutilans dietr, while O. delticola prefer green remnants. Both S. tumidus and O. delticola use low habitats all year round, while A. azarae and O. rutiland show seasonal variations in their habitas preference. In neither case, seasonal variations were associated to food availabilty. We suggest that the morphological adaptations to amphibious life of S. tumidus and the climbing habis of O. delticola made these species more efficient in low habita that A. azarae and O. rutilans. In the latter species, the seasonal variations of their habitat use seen to be a strategy used by populations to avoid the negative efects of extreme temperatures.