Dandelion and vole interaction

Like many rodents, the water vole is able to reach high densities in meadows. During outbreaks, voles cause significant changes in plant communities. Although water voles consume a wide variety of plant species, dandelions have a unique position: they are selected by voles year-round and serve as a key resource during winter. Voles harvest all parts of the dandelion and store the roots in almost monospecific food stores. As dandelions are perennial plants that take years to grow, vole activity can significantly affect dandelion populations. Our aim was to estimate the influence of dandelion density on vole space use, particularly habitat selection during natal dispersal. We tested the hypothesis that voles select dandelion-rich plots for settlements. We also measured the variation in dandelion density due to new colony settlements to assess potential feedback effects. We hypothesized that voles decrease dandelion populations. To achieve that, we used a drone to monitor dandelions and voles over two years. We monitored 52 quadrats, each half a hectare, three times a year. We analysed each image using remote sensing to locate voles and dandelions, and then examined the interactions between their locations over time. We found that dandelion-rich plots were more likely to colonize. In plots with low dandelion density, areas denser than the plot average were also more likely to be colonised. We observed a decrease in the number of dandelions after colony settlement. Finally, we found evidence that existing burrows were more likely to be reused by new voles if dandelions were still present. This study demonstrates that dandelion density is a key criterion in habitat selection for water voles and that vole colonies rapidly deplete this resource after establishment. These findings provide insight into plant-herbivore interactions and offer valuable perspectives for further exploration of the plant hypothesis, particularly with respect to the dynamics of resource availability and its role in cyclic population fluctuations.