Curbstone Valley Farm: Got Gophers?

Dear Readers,
The kind folks at Curbstone Valley Farm posted this on their fine blog and website and allowed me to repost it. Enjoy!

Curbstone Valley Farm: Got Gophers?
***some images and video not for the faint-hearted***
We have pocket gophers. Lots of them. We try very hard not to interfere with native plant and animal species on the property. However, in the garden and orchard areas we occasionally find we need to address our pocket gopher population. Burgeoning populations can quickly decimate rows of crops, kill small shrubs and trees, and do significant damage to underground irrigation systems.



Valley Pocket Gopher - the mortal enemy of young fruit trees

When we first moved here it was clear that in some parts of the property we had a healthy pocket gopher population. We knew that some degree of effective gopher control would need to be employed to protect our investment of newly planted fruit trees in the orchard.
Our goal was not to eliminate all gophers from the property. That’s neither reasonable, nor desirable. Although pocket gophers are damaging to crops, they do have benefits. They bury organic matter in the soil, increasing soil fertility. They aerate soils, preventing compaction, and increasing water penetration, thereby decreasing run-off. Their burrow systems are often utilized by other species, including our resident Coast Range Newts, as valuable shelter from weather and predators. Gophers also help to increase the rate of soil formation by bringing subsoil materials to the surface, where they are subjected to weathering. A few gophers aren’t necessarily bad, we just want to prevent the population from getting out of control.


In addition to powerful jaws, pocket gophers have long sharp claws

Five species of pocket gophers are found in California. The Botta’s, or Valley Pocket Gopher, Thomomys bottae, is the most widely distributed in this state, and the species we have here. Various species of pocket gopher are found throughout the western two-thirds of the United States, and parts of the southeast.
Regardless as to species, they are all controlled similarly and there are numerous legal methods of gopher control. Popular control methods have included baiting with toxic baits such as Strychnine-treated grain, or anticoagulant rodenticides, or hiring a certified professional to fumigate with aluminum phosphide.
We weren’t interested in using any toxic methods of control, not just to protect our own animals, but also the wild birds and animals here, and to eliminate any risks of residue run-off into the two creeks on the property. We consider this property to be sensitive habitat for numerous native plant and animal species, and have no desire to risk their populations for the sake of controlling a few gophers.
Non-toxic methods of control include trapping, barrier-exclusion methods of control, such as lining garden beds with hardware cloth or gopher wire, wrapping root-balls of sensitive plants in gopher wire, and encouraging natural predators to assist us in keeping populations in check. In the non-cultivated areas of the property we rely on natural predators to keep pocket gopher populations down. Our resident hawks, owls, coyotes, and bobcats are all natural predators of gophers, as is this gopher snake. But honestly, how many gophers can a gopher snake eat in a year?


The Pacific Gopher Snake (Pituophis catenifer catenifer) can't eat enough gophers to control large populations

We caught this bobcat earlier this year catching a gopher, with a side of salad, near the chicken coop.
Video: Bobcat Catches a Gopher at Curbstone Valley Farm
Unfortunately, the bobcats can’t reach the gophers running amok in our fenced orchard, and even if they could, they don’t consume enough of them, often enough, to significantly affect their populations. That’s where trapping becomes our best option.
We’d tried Macabee traps previously, but we had very rare success using those traps.
Unfortunately, the bobcats can’t reach the gophers running amok in our fenced orchard, and even if they could, they don’t consume enough of them, often enough, to significantly affect their populations. That’s where trapping becomes our best option.
We’d tried Macabee traps previously, but we had very rare success using those traps.


Macabee Trap - 'Old Reliable'...wasn't. We had poor success with this time-consuming trapping method.

Our soils here are friable, and it’s difficult excavating down to a horizontal run to place pairs of traps, without collapsing the tunnels completely. Macabee traps also aren’t very humane. They impale the gopher, but they’re not instantly killed. They bleed to death, slowly.


Cinch traps are easier to use than Macabee traps, and a more humane method of trapping

We had tried Cinch Traps, and had even less success with those. They are more humane, as they instantly kill the gopher, breaking its neck. What we didn’t realize was there is an art, and a science, to using Cinch Traps correctly, and successfully. Fortunately for us, we have an excellent local resource available, Thomas Wittman.
Thomas owns and operates Gophers Limited, in Felton, California. He teaches farmers, grounds keepers, and individual gardeners how to evaluate and control their own gopher populations. Desperate to squash the gopher problem that was gnawing its way across our orchard slope, we spoke with Thomas about doing an on-site evaluation and personal training session to teach us what we were doing wrong, so we could effectively trap our gophers. Thomas however recommended that we begin with one of his ’starter kits’, which included two traps, a hori-hori knife, and an in-depth instructional DVD. If after watching the DVD we still weren’t successful at trapping gophers on the property, he’d be more than happy to set up a private consult.



Our starter kit included this instructional video

We purchased his ‘Cinch Method Starter Kit’, and watched the video. We learned a lot more about gophers than we realized there was to know, and finally understood why our previous trapping attempts had been met with such limited
success. Thomas taught us how to think more like a gopher, how to read important patterns in soil disturbances, and most importantly where to place the Cinch Trap, and how to properly set the trap for greatest success.
The next morning, eager to deploy our new found knowledge against the gophers that had previously outwitted us, we set two traps. Thomas demonstrates placing the Cinch Traps in this video excerpt.
Video: Gopher Trapping Using the Cinch Surface Method (see gopherslimited.com)

We didn’t expect to be as successful as Thomas is in this video, as we hadn’t caught a gopher ourselves in months, but before lunch, we’d caught our first TWO pocket gophers in the orchard. Thomas’ kit had already paid for itself as we now had finally caught the most problematic gophers threatening our new fruit trees. As our gophers are killed without toxins, rather than bury them, we leave them at the soil surface. There are plenty of predators and scavengers here, and by morning they’re always gone.


Our first catch of the day

Ever wonder why these little rodents are called pocketgophers? I’d never really thought about it before. Pocket gophers get their name from their extensive external cheek pouches. Fur-lined pockets that extend all the way back toward their shoulders. They can pack a lot of food into these pockets, and transport it through their burrows, leaving their teeth and claws free for digging.


Pocket gophers transport food in their extensive external cheek pockets


Turning out this gopher's pockets revealed an entire crimson clover seed head

We took a little video of our first two successful catches. The video starts with a gopher underground tugging on the roots of some weeds (you can see the plant ‘twitching’).
Video: Checking Gopher Cinch Traps at Curbstone Valley Farm
We don’t usually recommend specific products on our blog, but if you have a seemingly endless supply of gophers, and are interested in non-toxic control of your resident gopher population, we highly recommend Thomas Wittman’s DVD. It was a good investment for us, and we finally feel confident that we can keep our gophers under control. If you reside in the San Francisco Bay Area, Thomas also does presentations throughout the year, in various locations. See the Gophers Limited website for upcoming sessions.

Living With Skunks

The very idea of skunks make people nervous. A skunks natural defense mechanism - you know the spray, makes them a very undesirable neighbor. But, there are so many skunks around it is almost impossible to avoid them or at least smell them. I get numerous calls about skunks in my business especially by irate dog owners or folks who have those great little cat or dog doors and end up with a skunk in the kitchen eating kibble. This post hopefully will give you some ideas on how to avoid the problems associated with skunks and begin to understand these beautiful animals that we live with.

First of all, there are times of the year when skunks decide that there are better places than the woods (what little is left in urban and suburban areas) to den. The oncoming colder months often drive them under decks and into basements and then in the early spring the need for a safe place to rear their kits. A lot of spraying occurs during mating and then again to protect their dens. I receive the distress calls at these times. Sometimes it is just unpleasant for people and sometimes people are alergic or sensitive to the odor and they have to vacate until the smell goes away.
When I get a call, the first thing I do is to discover for certain if there is a skunk residing under a house or deck. This is usually easy to detect if there is a lingering odor and there are signs of skunk digging and an obvious point of entry such as basement vent that is torn open. Sometimes like in decks that are open all around, the only sign is the odor. Once I am fairly certain the skunk or skunks are there, I determine if the space can be closed up and the animal(s) eventually evicted and excluded. This is easy in the case of a torn open vent but can be more difficult around decks. In the case of decks harboring skunks, I recommend digging a trench arond the edge and putting in a wire barrier about 1-2 feet deep with an "L" bend at the bottom facing out.
Once there is an exclusion option or even if there is not, the next step is to start the eviction process. I like to use Pine Sol and I spray it into the area using a fertilizer bottle on a garden hose. I put the Pine Sol in full strength and set the fertilizer bottle at highest level. Then, I wait until the evening, just before skunks usually emerge and spray the area trying to reach the deep, dark places . Don't worry, I never see them come running right out, skunks are very cautious, they come out later when things are quiet. Often, neither myself nor my clients see them emerge. The next day, and especially if there is a barrier with one opening, I put a piece of cardboard over the exit and see if the cardboard or paper is pushed in or out to determine if the animal returned. At this point I install a one-way door on the opening to ensure that if an animal is still inside it can exit. At this time of year (Spring), I must be very careful not to separate a mom and kits. So, I leave the door open and continue to spray for a few more nights. The mom will relocate the kits and then the sealing up time is right. In the case of an area like a deck that can not have a barrier, constant spraying will do the trick.
In the event of skunks or other animal getting into the house via a cat or dog door, there are a few ways to handle this. You can bring your inside animal at night and not use the door, you can close the door as early as possible in the evening or you can get one of the doors that require your animal to wear a magnetic collar to get in. If you feed your animals outside, particularly cats, then put the dish away at night so you don't attract other animals.
There are only a couple of times one would resort to catching a skunk in a trap. One is if the animal is obviously sick, in the case of a skunk this is usually seeing one during the day or if it is aggressive. It is better then to call the animal control folks in your county or city. Another is if you are unable to evict the animal. In this case you must ascertain if kits are present and be sure not to trap if they are.
Trapping a skunk is easy, I use a special trap called a "Durapoly" live trap that is enclosed and is more comfortable for the skunk or any animal than a cage trap and the skunks rarely spray. I install a view window in these trap so the trapper can be sure of the catch. I usually use dry cat food. Once you trap a skunk, I recommend that you bring it to the SPCA or a wild animal rescue place. Often the same organizations do provide trapping services. They will be able to ascertain if the animal can be rehabitated or if it is not healthy euthanized. This is an example of why trapping a skunk may not be a good idea, you may be ending the animals life as well.So to recap, first be sure you have a persistent problem and not just a one time occurrence; look for ways to evict and exclude to animals for a permanent solution and lastly trapping is the last resort.

Live Trapping Gophers

Live Trapping Gophers

Sometimes trapping a gopher live is a preferred method. If you are a researcher, a non violent gardener or if you just want to catch and release, I have a trap and technique that works well. One thing about releasing gophers in other locations though, it can cause new problems in an environment or in the case of suburban release may even cause a major feud So if you are relocating a gopher be sure it is in an appropriate place.

There are a couple of other things to consider when handling a live gopher. First, gophers use their teeth like another hand and they will use them to grab on to things, including fingers. The way to handle a wild gopher is to transfer the animal in a way that doesn't require direct handling. You can also pick a gopher up like a kitten, by the scruff of the neck, some pick them up by the tail. I have heard of people actually taming a gopher and keeping it like a hamster or guinea pig and if you think about it they are similar. Lastly, gophers can not tolerate being in the trap for any length of time so the trap must be monitored carefully. The technique I will describe takes very little time and you should be able to catch a gopher in a half hour or so.

The Gophers Limited Live Gopher Trap

The trap is a box trap that has a bottom mesh, one mesh end and a door that swings from the inside top down to the closed position. The trap is triggered when the gopher tries to close up the end from the light. Gophers will always plug up a burrow after they are done cleaning out and extending their burrow. This "plug" is usually very obvious in the center of the crescent shaped mound. Once opened, if the burrow is fresh, the gopher will close it. It is kind of like your front door. If you found it opened unexpectedly, you would wonder what happened and close it. The gopher is the same way and "closes" it by packing it full of soil. In this case it has to travel to the end of the box trap to do so. When it gets to the end it pushes on the mesh trigger and the rear door swings shut. When the gopher tries to get back out it closes the door more tightly.



Find the burrow plug - it is the circular area in the mound



Enlarge the opening so the trap is snug and not letting in light except at the end



Check the trap often and do not leave set for long periods of time



The key to making this all happen quickly is to trap as soon after dawn as possible. That is when gophers are most active and often you will find burrow entrances already open and with very little effort the trap can be placed. Trapping in this period is not only the most productive time but also the time when the gophers ability to survive the trapping is greatest.

Good Luck and happy trapping. You can buy this trap at my web store or you can try to construct one yourself with the diagram below. The trap I sell is a very sturdy and well made trap and should last for generations. Available at http://store.gopherslimited.com/

Ground Squirrel Control Without Poison

Ground Squirrel Control Without Poison

I have spent a lot of time working with the California Ground Squirrel. This animal can be a great nuisance in any situation where the squirrels and people try to co-exist. There are some problems with digging under structures, digging large burrows that stock animals and children can trip in. But the major problem is the fact that they are community animals and therefore are vectors for diseases. Two in particular rabies and Bubonic Plague (there was a case of plague last year in Monterey County). This is mostly due to fleas. Animals that share burrows almost always have fleas. When it comes to school grounds and public areas the squirrels cannot be tolerated. In agriculture I have seen ground squirrels steal corn crops, nuts and damage many other crops. If you have them, you will need to eventually find a way to control populations or eliminate them as much as possible and keep breeding populations extremely low.

I have tried many traps, lethal and live and finally found a trap that works well enough to really help solve the problem without spending a lot of time at the job. This technique can be very useful for public areas and schools because the trap is used for a very short time after a period of pre baiting.



Instructions for the Black Fox repeating Ground Squirrel Trap

This trap is great for Ground Squirrels and Prairie Dogs. The action that is different from other live traps is that the Black Fox trap takes advantage of the social nature of these rodent species. Ground squirrels and Prairie dogs are always curious about new things in the environment and will avoid them until they are comfortable. These animals work as a social group. You will see one or two always watching and warning the colony of impending danger. They are always aware of what the other animals in the colony are doing. Because of this behavior the area where trapping is to be done needs to be pre baited and the trap needs to be locked closed during this period and present near the pre baiting area. I advise trappers to put bait out for 5-7 days and see when the animals are readily feeding and eating all the bait every day. You want to create a feeding frenzy, not adding too much food but enough so that you draw a crowd. The object is to catch most or the entire colony in one trapping session. On the seventh morning, if the animals are feeding readily, place the trap right on the bait pile and put some bait inside as well as scatter a small amount by the door openings. Try to be sure the trap is flat on the ground and if possible settle the trap so some soil covers the bottom wire of the trap. Open the two door covers and you are set. Try to get back to the trap by noon or so and you should have a good catch by then. If you don’t check on the trap in a few hours the animals will probably not survive in the trap. When you have a catch then you need to do something to the animals. Some farmers and ranchers drown them and others use a euthanization chamber . You can make this out of plywood or use any plastic container the trap will fit in. Here is a photo of one that works well. CO2 is the preferred gas but sometimes in the field auto exhaust is an OK substitute. kill boxThis box has one side that opens to slide the trap in and hole the size of a shop vac hose to connect to exhaust pipe. 5-7 minutes are usually enough, adding a Plexiglas window would be helpful.
Baits: red oats, bird food, dog food, chicken, french fries, apples, cabbage and greens, corn – you may have to experiment to find the right bait.

Why Poisons Are Not In My Bag For Gophers and Moles

Dear Readers,
Here is a recent letter a concerned parent sent me:
"Hi Mr. Wittman...I called you today in regards to my daughter's gopher problem in her suburban backyard in Danville, CA. A local pest company tried by putting strychnine granules in the tunnels only to have the gophers push it back out. Not a good answer to the problem since she has two toddlers who love their back yard. The kids were playing in the soft dirt and the green granules were in the soft dirt apparently not placed in the correct tunnels. Being a concerned grandmother, I'm all in favor of trapping the rodents while the kids are not home. The backyard has actually been off limits since this all became a very scary POISONED play yard. She has three of four new mounds a day."
This is not the first time I have heard of this and I know it won't be the last. I have heard many stories of birds eating poisoned grain and dying right on the lawn and many stories of pets and wildlife (especially owls) that have been poisoned by mistake. This is mostly due to a lack of understanding about the nature of the target animals and the poisons themselves.
Today, professionals usually use for gophers a tablet that turns into a gas called Phostoxin. When applied to a fresh gopher mound it is usually very effective. You need a license to apply it and the secondary or accidental kill rate is very low. The applicator is usually the one in danger but I have heard of accidental poisonings with this material also including the death of a child. But in terms of residual poison left in the ground, there is none.
Poisons that are available to non professionals, like strychnine and anticoagulants are much more dangerous to kids, pets and wildlife. First the strychnine baits are usually coated over seeds, usually milo, a common round bird seed and colored bright green or green blue. This seed flows easily from dispensers like funnels and poison metering probes. When put into a gopher tunnel it is usually fatal but sometimes the gopher pushes it back up out of the tunnel. When used for moles it is completely ineffective as moles or carnivores and do not eat seeds so they usually push it back to the surface. Birds are the ones who usually end up eating it but so do other seed eating mammals like mice, etcetera. But as in the letter above young children see it as candy and may eat it. So my advice is to stay away from poisons and especially strychnine.
Antocoagulants are the next most popular catagory and they are fatal only after the target animal eats the grain or raison coated bait for several days, allowing the poison to build up in the animals body until internal bleading causes death. Though not as dangerous to a non target animal ingesting one dose, this can be a problem when predators like hawks and owls eat the poisoned animal. There is a lot of documented evidence of secondary poisoning of wildlife.
So, I say trapping is the best strategy and I have developed methods that can be as effective or more effective than poisons. I offer this information to you on my website and can supply you with the tools to achieve gopher, mole and other small animal control easily and without endangering other animals, people or even our water sheds and marine environments.
Thanks for listening,
Thomas

Live snaring Gophers

People often ask me at lectures about live trapping gophers to relocate them. You can catch a gopher in their main burrows using a special trap called a Sherman tram. This aluminum folding trap is used by many researchers to catch all kinds of small rodents and can be effective but requires constant monitoring as gophers can only live so long in them, usually just a few hours. As gophers do come out of their burrows at night, traps like a small Havahart can also be used baiting them with onions or carrots. Again, if you were to leave this trap out all night chances are that the gopher would probably die of exposure before you got to them in the morning. This not only defeats the purpose of live trapping but also is not humane in the least.
I pondered this a lot in my business as I like to study gophers and then one day my daughter, 12 years old at the time, told me of a fellow student who, during morning break and lunchtime, was catching gophers every day, putting them into his lunchbox and then releasing them after school in a nearby meadow and saving them from the trapping program that was in progress by the maintenance staff.
So my daughter told me he just used a piece of string and a couple of pencils. I asked her to investigate and learned the very useful "two pencil" method of snaring gophers. I found it to be a great and effective method and kind of fun as well and much akin to fishing.
The setup is simple. You take a piece of cotton string about ten feet long and tie a small loop in one end, then pass the string back through the loop to make a loose snare. Place this loop around one of those open gopher holes that you see usually in the morning or during the day. Often you can tell by dark moist soil marking the spot. Place the two pencils next to each other so that they are by the gopher burrow hopefully opposite the direction the gopher is coming out of. You can tell this by the fan of soil that is pushed out by the gopher. You want to be opposite the fan of dirt. Then take the loop of string and lay it around the burrow with the knot of the small loop against the pencils so that when you pull the string, the pencils will hold the knot in place and allow the larger loop to snare the gopher around the chest. Then play out the string and relax on the ground in a prone position and act like you are part of the scenery.

Soon the gopher will come popping up to check out what is going on. Wait till he is going in and out digging and pushing soil and then just give the string a light tug and you may have got him.
Keep tight tension on the string and lift him into a convenient container like a bucket or lunchbox. Relocate as soon as possible and put some soil and grass in the bucket so the gopher can stay cool. Relocate to a spot where the gopher may not encounter an angry gardener or lawnkeeper - so zen and karma free -aahh. Keep doing this until you are gopher free and then you may want to start visiting neighbors.

Installing Gopher or Mole Wire and Baskets Under Lawns and Plants

I get a lot of questions about the proper way to install a wire barrier to prevent gophers and moles from damaging lawns. This can be one of the most costly mistakes one can make when installing a new lawn. The cost of the installation is high as it is and then the extra cost of the installation of the wire is daunting. However, in areas of mole and gopher populations this step is worthwhile if done right.

I have seen many installations where the wire used was aviary wire, like chicken wire but with half inch diagonal mesh instead of one inch. This kind of wire was not meant to be buried and will fail in a short period of time. My choice of wire is to use either galvanized hardware cloth with one half by one inch openings or "gopher wire" wire made specifically for burying underground. One brand to consider is "Diggers" gopher wire which is a three quarter inch galvanized mesh and soon there will be available a stainless steel mesh.

If the sod is installed directly on top of the wire gophers will go under it and pull the grass down through the wire and moles will push piles of soil up through it defeating the purpose of the extra expense. Proper placement is to install the wire and then cover it with one to two inches of soil and then lay the sod on that. If you exceed one to two inches then gophers and moles will just tunnel in between the sod and wire.

Contractors sometimes try to talk you out of this extra step but be firm, this is the step that makes the extra expense work. Below is the first stage of laying the wire. I like to see the wire laid so that the leading edge of the wire or the part the is shingled under the next is toward the invading gopher or mole. This usually means that if the lawn is next to the house, the second row of wire goes under the first and so on. Just think of the animal tunneling under the wire. You want the seams to be layered so that if there is a small opening it is away from the direction of the tunnel.





Next you see the overlapping and soil is added as the sod is laid. The wire is held in place with sod pins or landscape staples







The staple placed about 2 to three feet apart. Again be very careful to have tight overlaps of 4-6 inches without buckling or openings.

Sometimes a vertical barrier is more appropriate for a garden area or to fence a wild area and home area. I recommend a trench 2-3 foot deep and install the wire with a ninety degree bend to the outside. Because gophers also invade from the surface, an above ground portion of at least six inches is needed also. Sometimes this can be tied into a fence or border



Gopher Baskets are very easy to use and install and I recommend them for perennial plantings, especially young fruit trees or roses. You can make them out of gopher wire or hardware cloth again stay away from making them with chicken or aviary wire.








Below is the kind of damage you can avoid with proper wire placement.




If you have questions and comments please email me or comment here. My web site is gopherslimited.com