As a prey species, voles have a high reproductive rate coupled with a brief life span. They breed early and often. My cat doesn't eat them - just leaves them on the deck as a "thank you" for the food that magically appears in his food bowl. I've seen a red fox in the winter snow pause, head tilted and ears pricked forward, then two-foot pounce into the snow. Muzzle into the snow, head toss sending stunned vole into the air. Single gulp, and stroll continued into the woods. I've heard coyotes, not seen them. Voles, I'm sure, are part of their diet. Ditto for the very infrequent black bear that comes around, across the river from Pennsylvania. We have red-tail hawks. They hunt well in summer, but if there is snow the hawks cannot find the voles in winter. Owls hunt at night, take mice that scuttle around in the dark. But voles, I believe, a creatures of the daylight. Snakes hunt in summer, sleep in winter. Anything that's this popular on the predator menu needs to keep their numbers up. Just wish they'd dine on something other than bulbs, roots of hosta, Hakonechloa, rose bushes, and more. Judy in semi-rural New Jersey.