
Voles, voles, everywhere.
As the
Idaho Mountain Express reported last week, much of southern Idaho is experiencing a vole population explosion this summer.
Montane voles are small but stocky rodents that live in large colonies. You might see them scurrying across the road or trail. Or you might notice their well-developed trails through sagebrush, meadows and agricultural fields.
Some reports point to this vole abundance as a sign of nature "out of balance," an assertion that is not correct.
Voles populations are cyclic, and at times the little animals exist in staggering numbers.
And wherever there are large numbers of prey animals, there will be a lot of predators taking advantage of the situation. Whether it's
wildebeest in the Serengeti,
mayflies on a
spring creek, or snowshoe hares in the Arctic, huge masses of prey invite a feeding frenzy.
And that's certainly the case with high vole populations. So many predators eat voles--foxes, coyotes, hawks, owls, weasels, snakes.
And, oh yes, trout.
Visit
Silver Creek in the evening and note the high numbers of owls around. It would be interesting to know if the owls have more young, or raise young more succesfully, in years of peak vole abundance. In Alaska, lemming population booms mean more breeding by snowy owls and short-tailed weasels. Perhaps voles--which are similar to lemmings--affect Idaho predators' survival and breeding success.
The concept of the "balance of nature" makes a good story, but it's never really been accurate. Nature sometimes appears, to human eyes, to be wildly out of balance. But huge population outbreaks are not necessarily plagues or natural disasters; instead, they're merely part of a natural cycle of prey and predator.
This summer, keep an eye out for voles and the many animals that eat them. It may be a while before we ever see this many again.