Numerical response of predators to large variations of grassland vole abundance and long-term community change

Voles can reach high densities with multi-annual population fluctuations
of large amplitude, and they are at the base of predator communities in
Northern Eurasia and Northern America. This status places them at the
heart of management conflicts wherein crop protection and health concerns
are often raised against conservation issues. Here, a 20-year survey
describes the effects of large variations in grassland vole populations on
the densities and the daily theoretical food intakes (TFI) of vole
predators based on roadside counts. Our results show how the predator
community responded to prey variations of large amplitude and how it
reorganized with the increase in a dominant predator, here the red fox,
which likely negatively impacted hare, European wildcat and domestic cat
populations. This population increase did not lead to an increase in the
average number of predators present in the study area, suggesting
compensations among resident species due to intra-guild predation or
competition. Large variations in vole predator number could be clearly
attributed to the temporary increase in the populations of mobile birds of
prey in response to grassland vole outbreaks. Our study provides empirical
support for more timely and better-focused actions in wildlife management
and vole population control, and it supports an evidence-based and
constructive dialogue about management targets and options between all
stakeholders of such socio-ecosystems. The data set includes: S1 kml file.
Location of the study area (can be dropped in a Google Earth window or
read from a GIS) S2 Excel file. Road-side counts (sheet 1) and list of
species observed (sheet 2) S3 Excel file. Small mammal data S4 Excel file.
Data for computing theoretical daily food intakes