Is this the year of the voles?

By Irene Shonle, CSU Extension in Gilpin County

Last year was a bad year for voles, but this year seems to be off the charts!  I have gotten many calls, and all of my colleagues are mentioning the same thing.   Now that the snow is melting off the lawns, people are looking in horror at the trails all over their lawns, and perhaps also looking at dead junipers or other shrubs from the voles girdling action.  

The high vole numbers may be due to the moisture we’ve gotten the past two years.  It’s caused a lot of grasses and forbs to grow luxuriantly, and this has led to lots of fat and happy voles that have of successful litters… which leads to …. more voles!

If you’re not sure whether you have voles or not, you may like to see this new fact sheet that helps identify what animal caused the damage you see in your lawn: http://extension.colostate.edu/topic-areas/natural-resources/burrowing-animals-determining-species-by-burrows-damage-6-521/

The good news here is that voles have pretty predictable boom and bust cycles.  Population explosions (right now) are followed by intense predation and other stressors that bring the levels back down.  So, even if you do nothing, you will probably find fewer voles in the future.  And it may bring a little comfort to realize how ecologically important the voles are – coyotes, fox, bobcats and hawks all depend on them.  In other words, we would never wish them to go away altogether.  And for that matter, they never WILL go away altogether.  If you have voles now, you probably will get voles again.

However, I think most of us would like them out of our gardens and lawns, especially when a few too many have moved in - like this:

Voles trails become apparent in the melting snow

To repair damage to lawns from runway construction, rake, fertilize and water the affected area.  The lawn should recover when the grass begins to grow.  Extensive areas may need reseeding.

For the most part, trapping is the fastest way to handle voles, and has the least potential to cause secondary environmental damage. It can seem daunting, but it is pretty easy to trap down the population that has settled in your yard in just a couple of days.  Poisons can be used, but there is the possibility of secondary poisoning of all the critters that could then eat the poisoned vole (including your dog or cat).  For more information on how to trap or use toxicants, please see: http://extension.colostate.edu/topic-areas/natural-resources/managing-voles-in-colorado-6-507/

Some preventive action in the fall can also be helpful – mow your lawn closely to reduce the tall grass that provides a safe haven for voles.  Since they are food for so many species, voles are rightly cautious in exposing themselves unnecessarily. If you live near an open space area, see if there is a way to mow a swath of the native grasses along the fence line to keep them from crossing over into adjacent lawns. 

Another idea – and this is not research based (yet anyway), but it does make a lot of sense to me, is to shovel a swath of your lawn in the areas where you usually see a lot of vole activity and damage in the spring-- similar to mowing the grasses above. Voles can move in to even a short lawn under the cover of the snow, since the snow keeps them just as safe as long grass does from predators.  If you remove the snow, it might just blow their cover.  I'm not suggesting you shovel your whole lawn -- just 5-10 feet by the fenceline where the voles get in. If you try this, please report back!