ABSTRACT
Animal space use and spatial overlap can have important consequences for population-level processes such as social interactions and pathogen transmission. Identifying how environmental variability and inter-individual variation affect spatial patterns and in turn influence interactions in animal populations is a priority for the study of animal behavior and disease ecology. Environmental food availability and macroparasite infection are common drivers of variation, but there are few experimental studies investigating how they affect spatial patterns of wildlife.
Bank voles (Clethrionomys glareolus) are a tractable study system to investigate spatial patterns of wildlife and are amenable to experimental manipulations. We conducted a replicated, factorial field experiment in which we provided supplementary food and removed helminths in vole populations in natural forest habitat and monitored vole space use and spatial overlap using capture-mark-recapture methods.
Using network analysis, we quantified vole space use and spatial overlap. We compared the effects of food supplementation and helminth removal and investigated the impact of season, sex, and reproductive status on space use and spatial overlap.
We found that food supplementation decreased vole space use while helminth removal increased space use. Space use also varied by sex, reproductive status, and season. Spatial overlap was similar between treatments despite up to three-fold differences in population size.
By quantifying the spatial effects of food availability and macroparasite infection on wildlife populations, we demonstrate the potential for space use and population density to moderate spatial overlap in wildlife populations. This has important implications for spatial processes in wildlife including pathogen transmission.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
This version of the manuscript has been significantly revised to utilize new methods for quantifying space use and spatial overlap. These methods better account for uncertainty in data by aggregating space use behavior across voles grouped by sex and reproductive status in a season to estimate average space use for each group. We then use these estimates of space use for each vole captured in a month to quantify weighted measures of spatial overlap. This approach limits the effect of capture frequency on measures of space use and spatial overlap and places less emphasis on the specific trapped locations of individual voles, allowing us to present a more holistic picture of spatial behavior under the experimental manipulations.
