Local population dynamics of small mammal communities in agricultural landscapes of SW Europe: density-dependence and relationships with climate

Resumen del trabajo presentado a la 10th European Vertebrate Pest Management Conference, celebrada en Sevilla (España) del 21 al 25 de septiembre de 2015.Understanding the ecological factors that determine the population growth rate of rodent populations is fundamental in order to study population dynamics, and to predict and better manage population outbreaks. This is particularly important for species that spill over diseases or cause significant crop damages when overabundant, like common voles in NW Spain. Using six-years of seasonal (three times a year) abundance data (July 2009-March 2015), we investigated weather variables influencing local seasonal population dynamics of Microtus arvalis, Apodemus sylvaticus, Mus spretus and Crocidura russula. In that way, we used General Linear Models (GLM) to explain variation in seasonal population growth rates (PGRs) of each species with abundance and climate variables (average temperature and monthly accumulated precipitation in spring, summer, autumn and winter). Winter was the most critical period for all species, as winter temperature positively influenced winter PGR. Moreover, winter temperature positively influenced spring PGR in M. arvalis and C. russula, suggesting that warmer winters benefited vole and shrew population growth during both winter and spring. On the other hand, precipitation was crucial for summer PGR in common vole, shrew and wood mouse, while winter precipitation influenced spring PGR in M. spretus. We discuss species-specific traits (e.g. diet, size and metabolism…) that can explain how climate affects population dynamics. These results allow a better understanding of how weather affects the local population dynamics of small mammals in a typical community of Mediterranean farmlands in south-western Europe.Peer Reviewe