As I was walking to the barn, I heard the loud squeak of a shrew from a nearby area of tall grass. It’s not unusual to hear shrews in the grass, but you normally hear two instead of just a loner. I peered down into the grass to see if I could get a look at the shrew. Instead, I caught a glimpse of a Meadow Vole zipping through the grass with a vole baby in her mouth. Then I found the rounded mound of grass that was her nest.
Inside the nest were five babies. I can’t prove it, but I believe the shrew found the nest and made off with one of the babies. The squeak was probably the shrew’s reaction to a confrontation with Mama vole. The female vole’s response to a nest violation by a predator is to relocate the young to another nest. A normal litter contains six or seven young, so this nest probably began with seven. That’s one for the shrew, one carried off by the mother and five waiting their turn to relocate.
This little guy will one day be a grass eater, but now it’s still dependent upon its mother’s milk. That’ll change rapidly. Meadow Voles are weaned when 12 days old. Females begin breeding at the age of 25 days. The mother vole mates immediately after giving birth, so her next litter is developing while she’s nursing the current brood. A gestation period of 21 days means that she can give birth about every three weeks.
These young voles are destined to die in the teeth, claws, beak or belly of some predator. Voles are just active little packets of food. They are the primary food of a multitude of mammals, birds, reptiles and even fish. Meadow Vole breeding goes on year-round, so it’s fortunate that so many creatures find this animal appetizing.
I covered the nest and went on my way. When I checked back a few hours later, the nest was empty. Litter relocation is a fairly rapid business, so I assume that these little guys are now off in a new nest.