Biological and environmental aspects of a mouse outbreak in the semi-arid region of Chile

Abstract

For climatological reasons there was a surplus production of annual herbs and grasses in Coquimbo Province, Chile, during 1972 and 1973. This availability of food caused a rodent [including Phyllotis darwini, Akodon olivaceus, Octodon degus, Mus musculus and Rattus rattus] outbreak, of which O. longicaudatus was the main component. The outbreak was studied at Asentamiento Ceres, La Serena, in May and June 1973. Sherman live-trap success was about 45%. These biological factors are responses to the oceanic-metereological phenomenon called El Nino.