Demographic, genetic, and physiological responses of montane water voles to trapping-based control across different...

The montane water vole (Arvicola scherman) is a major pest in grasslands and perennial crops, where densities may exceed 1000 individuals/ha and control campaigns often show variable effectiveness. While control methods have been widely assessed, little is known about the responses of surviving individuals or the influence of landscape structure on post-control recovery. This study evaluated temporal changes in population structure, body condition, and gene flow under a trapping-based control program across a heterogeneous landscape.

Three populations from the northern Iberian Peninsula (Oles, Priesca, and Fresnadiello), representing agrarian, mosaic, and forested landscapes respectively, showed contrasting demographic, physiological, and genetic responses linked to landscape context. Oles and Priesca exhibited high abundance in 2011 followed by sharp declines in 2012; Priesca partially recovered by 2013, whereas Oles continued to decline. Fresnadiello increased from low abundance to a 2012 peak and then stabilized. Age structure shifted toward adult dominance over time, while sex ratios remained stable. Body condition showed site- and sex-specific trends. Genetic responses paralleled demography: Oles suffered marked losses of allelic richness and heterozygosity with limited immigration; Priesca gained novel alleles through increased migrant input; and Fresnadiello maintained high genetic diversity, with indications of incipient inbreeding.

Population responses to control depend strongly on landscape structure and connectivity rather than demographic crashes alone. Effective management of A. scherman requires integrating removal intensity with dispersal context and adaptive monitoring to limit recolonization and ensure long-term control. © 2026 Society of Chemical Industry.