Population recovery of Mus musculus in poultry farms of central Argentina. The role of local and landscape features

LEÓN, V.A.; FRASCHINA, J.; GUIDOBONO, J.S.; CAVIA, R.; BUSCH, M.

Posdam

Congreso; 6th International Conference of Rodent Biology and Management & 16th Rodens et Spatium; 2018

Poultry farms in rural areas of central Argentina are dispersed within a landscape dominated by cropfields. The composition of the rodent community is very different between farms and neighbouring fields: In the first habitats there is a dominance of commensal exotic species, as Mus musculus, Rattus norvegicus and, occasionally, Rattus rattus, and native species are rare. In cropfields and longitudinal edges between fields or along roads there are native species, and commensal species are rare. In this work we want to answer the question: where the Mus musculus individuals that recolonise poultry farms after control come from? The alternatives proposed were: from the surrounding of the farms, from other farms, that they are transported by men, or from the population recovery of remaining individuals. To answer this question we have used different approaches: description of rodent communities in farms and surrounding habitats, genetic studies in order to estimate gene flow according to geographic distance, models that relate M. musculus abundance and environmental variables at local and landscape scale, tracking movements with fluorescent powders, with the experimental application of control at different spatial scales and with exclosure experiments. Our conclusion is that the abundance of M. musculus in poultry farms is mainly related to intrinsic characteristics of farms, that this species normally travels short distances, that immigration is from nearby farms and not due to passive transport by human or from surrounding habitats, and that dispersal movements are along cropfield borders or riparian habitats, and not through cropfields. Recovery after control is mainly due to reproduction of remaining individuals. An increase in poultry activity in the area with a shortening of distances among farms may cause an incresase in the levels of infestation by Mus musculus in these habitats, but probably not in other habitats.