Okay, first of all, thanks for your input!
I think I need to clarify this a bit: We have several species of voles here. What you’re describing (above ground, looking for plants) would be the common vole (Microtus arvalis) in our area; they’re also found in my meadow, but they cause me fewer problems in my garden beds (and are easier to catch there). The really nasty creatures are the voles (Arvicola terrestris), because those pesky beasts feed underground, mainly on roots, and can ruin both fruit trees and most types of vegetables.
I’d heard once that field voles and moles can’t stand each other (and in captivity, moles apparently even eat young field voles, though the natural relevance of that is perhaps rather questionable), which is why I asked.