nuisance wildlife control in gardens, with ohio state’s marne titchenell
MOLE OR VOLE, woodchuck, rabbit or deer? Who ate or uprooted my plants? By this point in the growing season, I suspect every gardener has faced at least one fur-bearing opponent, a creature that seems to want to either prevent the harvest or garden design we’re working toward, or eat the whole thing themselves.
All these animals are usually lumped in the general catchall of “nuisance wildlife,” but it’s critical to know specifically who you’re up against, to do the best possible job at prevention, or to devise a safe, sane and humane solution, if the unwanted animal is already in residence.
For advice, I called Marne Titchenell of Ohio State University. She is a wildlife program specialist in OSU’s College of Food, Agricultural and Environmental Sciences, and when I read about the popular workshop she gives to gardeners called, “The Good, the Bad and the Hungry: Controlling Nuisance Wildlife in the Home Landscape,” well, I knew she had the answers we were seeking.
Read along as you listen to the July 18, 2016 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here). Learn how to diagnose what animal is to blame, why habitat modification is always part of the solution, and in which particular instances repellents can help (not always!).
my nuisance wildlife q&a with marne titchenell
Q. I suspect it wasn’t just doing your bachelors and masters degrees that got you interested in wildlife and nature. Was it an earlier thing?
A. That’s true. I guess I would have to credit that to my parents. They were always getting my brother and I outdoors, and I think that was where my passion started.
Q. I think some of us get the bug early. Nowadays so many of us are living with what you call in your presentation, “wildlife conflicts”—living closer to each other, with suburban sprawl and so forth.
A. You’re spot-on. I daresay that our prevalence of wildlife conflicts has been increasing over the past several decades, and I think it is largely attributed to the fact that more and more folks are living in urban areas, as you say sprawling out into the rural countryside. So not only are we coming into contact with established wildlife populations as we sprawl out into these rural areas—and of course that’s going to increase the chance of conflict—but the wildlife are also moving into us.
Within our communities, whether we’re greening our communities for ourselves or in some cases we’re doing it to provide habitat for wildlife—but in our own backyards, when we are putting in gardens or landscaping, we are essentially creating habitat. Whether we are intending to do it purposefully for the wildlife or not, they are recognizing it and they are coming into it as well.
The critters you mentioned—the deer, raccoons, squirrels, chipmunks—they’re all very good at recognizing the resources that they need to survive.
Q. And they just can’t wait to get to know us better. [Laughter.] [Above, tomato partly consumed by a chipmunk.]
A. Yes, exactly. They co-exist very well with us.
Q. I suspect even more people approach you than me with “Something’s eating my vegetables,” or my hostas, or my fill in the blank with the name of the plant. But “somebody” isn’t enough information, is it; we have to be more of a sleuth, correct?
A. Definitely. When I talk to homeowners about managing wildlife conflicts, one of the first things I encourage them to do—the Number 1 step—is to correctly assess the damage. To really figure out what went on, and “sleuthing” is a really great way of saying it. Trying to gather as much information as you can.
Say a plant was damaged: Can you really get down there on the ground—or sometimes up high—and really see what that damage looks like. Are there jagged edges? Are there clean-cut edges? When do you think that damage happened—during the night, or during the day?
All of that information is going to really help identify the culprit, so it’s very important.
Q. For instance, it’s kind of a joke that I keep score in the spring when I first plant up my pots of annuals. Inevitably, I go out in the morning, and everything’s on the ground, and the soil’s all over the place [above]. So if I’m seeing that, I know it’s something at night—so I think skunk or raccoon, probably, but I don’t think squirrel. A squirrel might do that, and they love to dig in my pots and look for an acorn or bury an acorn or something, but they wouldn’t be doing that overnight.
A. And you’re right—it’s most likely raccoon, in my experience, that’s the culprit that digs up that plants. They’re searching for insects, for grubs, or anything that would be underneath the soil, and newly potted plants or even older ones are easy for them to dig up. They do that a lot.
Q. If someone tells me a plant was eaten, I always ask what the damage looks. How do you as an expert determine who it was—a rabbit, a woodchuck, a deer?
A. Sometimes just a little bit of information about the damage on that plant can tell you what was causing it. Deer are going to leave very jagged edges behind on that plant, and that has to do with their dentition. They have bottom incisors, but nothing on top. When they grasp a plant they’re going to pull, and it will rip very unevenly. [Above left, deer-browsing damage to tulips; above right, damage from deer rubbing tree trunks in the offseason.]
Whereas a groundhog or rabbit have those sharp upper and bottom incisors, and they’re going to leave very clean cuts.
You look at things like that, but then you also want to step back a little bit and look at what else is going on. Where was the plant damaged? If it’s lower to the ground, within 2 feet or lower, and you’re seeing those clean-cut edges, it’s probably a rabbit. I the damage is higher up, above 2 feet, it’s going to be a taller animal, like a deer.
In terms of the groundhog, usually those guys don’t feed very far from their burrows. They like to maintain a safe distance to that spot. Odds are if you’re having a lot of groundhog damage, you’re probably going to see some burrowing underneath a foundation, a porch or a home. So looking at the plant is good—but you also want to take it all in, and think about some of those other habitat needs of the animal.
Q. The rabbits are interesting—they make a perfect angled cut, don’t they?
A. Yes, it’s almost a perfect 45-degree cut [above left]. That is classic rabbit damage—and again the height, if it’s less than 2 feet, roughly about the size of a rabbit on its hind feet, you’re going to see that. More on green plants during the spring and summer, but rabbits are active during the winter and they’re going to switch their diet to more woody plants [rabbit damage to shrub, above right].
During the winter they also leave behind scat, or feces, and that’s usually pretty recognizable, especially on snow cover. I like to call them little brown Cocoa Puffs.
Q. Oh, that’s a good description, sort of. [Laughter.]
A. [Laughter.] Sort of.
Q. Oh, my, a new breakfast cereal. Rabbits are sort of my most loathed animal. I have an 8-foot deer fence because I am in a very rural area, and we can have herds of like 45 deer across the road. There is no way you could have a garden. After maybe 10 years or so of things being eaten to the ground, including many woody things, maybe 15 or 20 years ago I got a big fence.
So deer are not an issue, but I find rabbits very tricky, because they are hard to predict. A woodchuck as you said goes to its burrow—it’s methodical, and usually comes out a couple of times a day to feed. I can usually find him—notice I say “him,” how sexist of me [laughter]—but it’s a little more predictable of an animal than rabbits.
A. Rabbits need very little cover, and can definitely congregate heavily in areas where there is good habitat and good food. They’re definitely a little bit challenging.
You said you have a fence, and I wonder if you could put a smaller mesh down below? With rabbits, if you’re able to exclude them from the area where they’re causing problems, like a raised bed or a garden area, that’s often the best longterm solution. And that’s because they can multiply so quickly in favorable areas. So trapping, or lethally removing the population can sometimes be a challenge. Excluding them from the area, that’s good.
Otherwise you can try some less-tasty plants—some rabbit-resistant plants out there in your landscape as well.
Q. I’m not so sure they have the same plant list as I do. [Laughter.]
A. That’s true—and that depends also on how many animals there are, and how hungry they are.
Q. So we see something—we see damage—and we have to identify who it was that’s responsible, and assess the situation. And then we have to decide on a tactic. You might have a chipmunk digging holes in a certain place, and decide it’s not all-out warfare you’re going to declare (or at least that’s my approach with such a thing).
But we have to figure out what to do, the level of pressure we want to exert in the opposite direction, yes?
A. I say that’s every homeowner’s decision. Think about the problem, and assess the cost of damage versus the cost of management. Think about what damage they’re sustaining, and the lengths you’re prepared to go to, to lessen that damage.
It all goes down to the homeowner’s tolerance level. For some people, one single chipmunk is enough. Case in point: Just this past weekend, my uncle saw a chipmunk running across his deck, and he did not hesitate; he disappeared and came out with a little live trap. No tolerance at all, but at the same time my parents were sitting there and said, “Oh we have chipmunks all over; it’s OK, as long as they’re not causing a lot of damage in the garden.”
It’s really the homeowner’s choice what they want to do next. But I always encourage them to really stop and think about it. What’s it going to take to solve this problem? Do you want to go there? Or are you willing to adjust your tolerance level a little bit?
Q. I want to go back a minute to some animals people may mistake for one another. We talked about some bigger herbivores, like rabbit versus woodchuck versus deer eating the same plant.
One thing I find that people are stumped by is mole versus vole. They say, “I have moles,” but then they send me a picture and it’s not moles. So let’s talk about that—and actually chipmunk holes are another thing to mention.
A. Moles and voles, despite their similar-sounding names, are very different animals. They often are going to cause damage in the landscape. Moles are insectivores, so it’s going after insects, and it’s searching for insects and also worms and grubs underneath the soil. [Above, raised mole tunnels in turf, and mole hills of piled-up soil.]
So it’s a fossorial animal—or one that lives underground. Moles rarely come up above the surface. The damage you see is that they create those slightly humped and raised tunnels underneath your lawn, and sometimes it can be a rather long tunnel, or twisty and turny. But they’re just below that surface of the ground. When they’re burrowing and looking for insects, they often cause a separation of the grass roots from the soil, and that’s why after a time the grass on top can die.
Q. And if you walked on it, you could kind of press it down.
A. Yes, you can squish it down. So those are their feeding or foraging tunnels. Moles are also going to create those volcano-like mounds of soil, and they’re doing that because they’re burrowing a little deeper. When they’re burrowing just below the surface, they can push that dirt they’re displacing above them, and that’s what pushes the soil up and creates that raised surface.
But when they’re digging deeper, they do need to put the soil somewhere, and get it out of those holes. They push it up to the soil surface with their heads. That is classic mole damage.
Voles are a rodent, and are herbivores—like most of our rodents. They are going to be eating plant material and seeds and vegetation. They’re going to be above the surface—they’re spending most of their time above the surface. However, they create these little tunnels that are right where the grass meets the ground. And they will kind of clip the grass in those tunnels to make it easier for them to move through, and eating the grass as well.
These guys are active year-round, and definitely during the winter. Oftentimes you’ll have voles that are active underneath the snow in a homeowner’s yard, going through these little tunnels, and then when the snow melts you see all of these twisty, turny little tunnels right at the surface of the ground. [Below, vole surface tunnels, and vole damage to woody plants.]
Q. That subnivian layer—that little air space between the bottom of the snow and the soil surface—there is a lot of action under there.
A. There is, and that’s what they are taking advantage of. We don’t often realize it. So voles will do that, and in a landscape setting where there is mulch, they will sometimes travel underneath the mulch, so you’ll see a little tunneling there, and often girdling at the base of plants, or plant roots. That the kind of damage you get with voles.
Q. And they have big population swings. I have never seen this many as I have this year.
A. It won’t last.
Q. It’s to the point where I can identify the different species—I have meadow voles, and Southern red-backed voles.
A. Here in Ohio, it’s often the meadow vole, but every so often we see one of those others. You definitely have more to contend with. But yes, those boom-and-bust populations are very typical for voles, which can be very trying for a homeowner. One year you’re just overrun, and then the next year it’s not too bad.
Q. I have to say I don’t ever go after the moles; I press down the tunnels, but I’ve never had enormous damage. I love those insectivorous animals to go do their thing and aerate the soil. But the voles—I do confess to trapping them with mousetraps inside boxes [above and below photos] to hopefully protect other animals.
A. Snap traps are a good way to go, and with voles the general rule with trapping is to put more traps out within a shorter period of time than fewer over a longer time. You want to hit that population and hit it hard.
Q. Oh, so the same approach as with mice, but really load it up with more traps.
A. And just keep trapping until you stop catching.
Q. Or you could of course invite the local bobcat and gray fox to live in the yard, as I had all spring.
A. If you are lucky enough to have that.
Q. It was hilarious to watch them, from a safe distance, listening near the tall grass, then pouncing like cats and dogs will do. Unfortunately they didn’t take enough of them.
I bet if we tool a Gallup poll, squirrels would be the thing that drives people the maddest.
A. I find that, too. The reason is that they are difficult to manage. Especially with our tree squirrels, they get into everything; they climb. They can definitely be a nuisance. With squirrels, you have to think about what’s attracting them there in the first place.
Q. This brings up the habitat modification idea you cover in your workshop, which is so important. Like duh, if I have bird feeders out, guess what?
A. Exactly. There are lots of tools you can use to combat wildlife conflicts—trapping, repellents, resistant plants. But habitat modification: That’s what you should do 100 percent of the time, no matter what.
Even if it’s just stopping and thinking: Why is this animal here? Is it food? Is it shelter? Is it water? Why are they here, and can I modify that habitat resource?
Sometimes it’s a very simple fix, like with raccoons, skunks, possums: Is it a hole underneath the porch, or was the garbage left out? Is it pet food left laying outside? You get rid of that, boom, you’ve solved your problem—like you said with the squirrels and bird feeders.
Q. And that brings up exclusion—you just said a hole under the porch. If every year you have a woodchuck under your front porch, it might be worthwhile to do heavy hardware-cloth screening and even bury it.
A. Most definitely, and that’s one of the things that’s recommended. Making sure there’s nothing living under there currently first, of course.
Q. [Laughter.] That would be my kind of luck.
A. If you wait until August here in Ohio, it’s usually a pretty safe bet that animals who would be underneath the porch are out. The young have matured if it was a female. But there are still a few things I would recommend, like crumpling up newspaper and stuffing it in the hole. If that newspaper is still there after a few days, you know that hole is no longer being used, and you can permanently seal it up. The other option is to set a trap and see if you can catch anything.
Q. I would say with the caveat not to leave a large trap open at night, if you have skunks and raccoons. And that gets back to our thing of who is around—you really have to think about who you might catch inadvertently if you get into trapping.
That brings up the ethics of trapping, and we should say there are laws in every state about what you can and cannot do. We can’t as citizens be putting animals in our cars and driving around and letting them out in someone else’s yard or a state park. That’s, generally speaking, against the law.
I actually think if people think they need to trap, they should get help at first—from a nuisance wildlife expert. And I will say: If I have an animal that needs to be relocated, I do work with a licensed person for the relocation part.
A. In pretty much every state there are professionals where it is their job to deal with nuisance animals. So if a homeowner is uncomfortable trapping themselves, or as you said just unaware of the laws, it is a good thing to call a professional and get some help.
Q. We haven’t even talked about deer—I’m afraid to even bring it up. You’ll have to come back and do a whole show about deer. But before we run out of time:
Repellents. I have to say they’re expensive, and I have a big garden, so they’re not my thing. When are they useful?
A. They tend to be most useful most often with deer and rabbit, and when you’re having a little bit of damage. If you’re not having moderate or severe damage, then repellents could be a good option. But if you’re having a lot of plants being eaten, that’s telling you several different things. There could be a lot of rabbits or deer in your area, or they could be dependent on your food source.
So something like a bad taste or a bad smell isn’t enough to deter them.
But if you’re just having a little bit of damage, repellents can definitely work. With those two species, the ones on the market right now that research indicates are working best are hot pepper and eggs.
Q. The rotten, putrefied egg solids?
A. Yes, the rotten smelly ones. [Laughter.] Those tend to be the ones that work the best. If you look at some products out there, you’ll see that they are using both the hot peppers and the egg solids in their products.
more from marne titchenell
- Marne’s faculty page at OSU’s website
- OSU factsheet by Marne on Canada goose conflicts and management tactics
- Lecture (in video format) by Marne on attracting wildlife to your landscape
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MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its seventh year in March 2016. In 2016, the show won three silver medals for excellence from the Garden Writers Association. It’s produced at Robin Hood Radio, the smallest NPR station in the nation. Listen locally in the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. Or play the July 18, 2016 show right here. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).
(Photos courtesy of Marne Titchenell, except of chipmunks, trapping boxes, and emptied pots. Top-of-page garden “doodle” by Andre Jordan.)