Last year, my sweep of Acorus gramineus in the front gulley was devastated. I first noticed some browning and went in to investigate with rake in hand. To my horror, not only the brown, but huge clumps of seemingly healthy sections came out. At the bottom of each one was a jagged edge. Upon closer inspection, I could see the plants’ fleshy roots had been eaten. My conclusion: voles.
Voles are burrowing rodents – similar to moles. They look like field mice with a little longer nose. They prefer grassy, low lying areas and wetlands. Where moles cause damage in their burrowing, they are after grubs and worms. On the other hand, voles eat your plants. They prefer things with fleshy roots, but are not above sampling others. My theory about this invasion was the loss of nearly all the outdoor cats on our street over the past 5 years – likely due to coyotes or raccoons. The voles were unchallenged. I checked around with other landscapers and found that they too had seen a rise in numbers, so my vole invasion was probably part of a larger population boom.
I love this part of my garden and was very troubled by the damage. Poisoning was not an option. Voles are part of the larger food chain, and anything that poisons them in a bait station could also poison whatever eats them while the voles are still alive or once dead – such as coyotes, eagles, owls or even cats & dogs. Most rodent poisons are anticoagulants. Not nice at all. Body gripping or kill traps were out of the question with no explanation needed. I started with Mole Mover ultrasonic devices even though the data about use with voles was sketchy. The damage seemed to abate for a while. Then, this spring I noticed the piles of dirt again and knew I had to take further action.
A little research and purchase on Havahart’s site (www.havahart.com/ ), some peanut butter and…well…the voles got new homes. Let me tell you – they love peanut butter. When I first started, I’d set a trap at dusk (they are nocturnal) and within a few minutes I’d hear the click of the trap doors. Since organic peanut butter was all we had when I started this experiment, they were living the luxe life. My success led Adam to keep track of the “vole toll” on our chalkboard…
Then last night, a new development in the vole vs. Tish saga: reinforcements. At dusk, we were breaking up one of the usual animal squabbles (Lola (cat) 1, Owen (dog) zero), and Adam called me over to the window in a hushed but very excited voice, “Come here…NOW.” Sitting on a branch about 10 feet off the ground and literally staring in our kitchen window, no doubt entertained by the antics, were two large owls. Once noticed, after some head bobbing, they both flew to another part of the garden. We crept out quietly (after securing Owen in the car because by this time he knew something was up), and were treated to even lower perches in another part of the garden, and flight directly overhead. They were scanning the ground and calling out to each other with a high-pitched eerie hiss. They were hunting! We ran back inside and grabbed the bird book, and checked out The Cornell Lab of Ornithology Bird Guide – a fabulous resource all about birds and aptly named this – www.allaboutbirds.org. Through their sample recordings, we concluded that our visitors were barn owls. Then the good part from the bird book - ”A barn owl can eat up 1,500 rodents a year.” Wonderful. Welcome my friends, make yourselves at home and enjoy the plethora of food (note: our cats are indoor).
For now, I’ll sideline the traps and let nature take its course. We have heard these guys in the neighborhood for a few weeks now, the screech is unmistakable. They seem to have set up home close by. Watch out voles!