Habitat Preferences Of Sigmodon Alstoni And Zygodontomys Brevicauda (Rodentia, Cricetidae) In Agroecosystems Of The Venezuelan Plains

The habitat preferences of Sigmodon alstoni and Zygodontomys brevicauda in agroecosystems of the Venezuelan llanos were studied. A total of 37748 Sherman traps were set in the field and 1624 individuals of S. alstoni and 1398 of Z. brevicauda were captured. The two species showed similar habitat preferences. Mechanized agricultural fields, mainly of sorghum and maize, and pasture, constituted their most important habitats. In a temporal axis, it was found that S. alstoni is more associated and uses with greater homogeneity the mechanized cultures, followed in sequence of importance by pasture and herbaceous vegetation. With respect to Z. brevicauda, the mechanized cultures are primary and it uses the pasture with less regularity, but greater homogeneity. It is intensely associated to herbaceous vegetation in brief time intervals. Because these rodents are vectors of Venezuelan hemorrhagic fever, it is necessary to monitor their populations in order to apply control measures. In agreement with the results obtained in the present investigation, the strategies of control should be directed towards the management of the habitat and human communities, sustained in programs of environmental, formal, and informal education, to diminish and avoid the contact of people with the rodent.