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Poisoning Ground Squirrels — is it right?

By Gary Bogue
Sunday, October 12th, 2008 at 10:02 am in Ground squirrels, Mount Diablo, Poison.

ground squirrel2

My column in the Times today (Sunday, Oct. 12) contains a letter from Kelly Adams of Clayton, California, complaining about two men from the Contra Costa County Department of Agriculture, who she caught scattering poison to eradicate ground squirrels in the open space on the slopes of Mount Diablo on the other side of her back fence.

Needless to say Kelly was more than a little upset at this.

ground squirrel3

I responded to Kelly’s letter and told her how I felt about using poisons to kill animals, especially in the open spaces on Mount Diablo, an island sanctuary for native wildlife in the middle of Contra Costa County. You can read my Sunday (today) column here at

We’ll continue the discussion on poisoning ground squirrels in my Tuesday (Oct. 14) column in the Times. you can read it by going to our newspaper’s Web site on Tuesday (Oct. 14) at and clicking on “Columns” at the top of the page and then scrolling down until you get to Gary Bogue and clicking on my name.

In the meantime, here are some additional comments about poisoning/eradicating ground squirrels for you to ponder.

Some thoughts on poisoning ground squirrels on Mount Diablo by Seth Adams, Director of Land Programs, Save Mount Diablo:

Our public open spaces are meant to protect wildlife. Even in private open spaces, poisoning ground squirrels is cruel and barbaric. But, some say, “it’s just a rodent.” No, they’re native wildlife and an environmental indicator of things that affect us all.

Throwing poison around affects people, too. Anybody claiming that poison is safe and nothing to worry about needs to explain why, if it’s so safe, applicators are told to wear gloves, respirators, long pants and sleeves, and protective eye wear. Claims that the poison doesn’t affect water is also bogus. Chemicals in the ground get wet, seep into ground water and are washed into creeks. We all live downstream of somewhere and while some poisons do eventually break down, often what they break down into is just as bad.

Despite the claims, poisoning does affect other wildlife.

It kills hawks and owls and other predators including people’s dogs and cats, especially if they eat the poisoned squirrels. So why does anyone do it? Ground squirrels like any other wildlife, can cause damage. But why poisons? One reason — it’s cheaper and easier than other methods, damn the consequences.

The problem is that most poisons and chemicals haven’t been tested for secondary or long-term effects, or synergistic ones as they combine with other chemicals — and most poisons are made up of many chemicals not just one. They’re like automatic weapons — we make one kind illegal, they change the model slightly and sell it under a new name. Same with chemicals and poisons — we outlaw one and another takes its place.

But we now know DDT killed millions of birds — and almost wiped out bald eagles, peregrine falcons and pelicans among many other rare species — just as we now know that the long term “safe” ground squirrel poisoning with arsenic at the Concord Naval Weapons Station has left large areas considered toxic and in need of millions of dollars of clean up.

Poisons don’t just go away — they linger and spread.

Ground squirrels are an important part of the food chain, and just as important, in our hot dry climate, many wildlife species including ones that are rare and endangered rely on ground squirrel burrows for survival.

In the future poisoning them will be considered as dumb as wiping out songbirds to decorate hats, dumping pollution into our drinking water, and killing wolves that keep other animal populations healthy by shooting them from airplanes.

It’s cruel, it’s short-sighted, and it affects us too. Find another way.
— Seth Adams

Thanks for the input. I couldn’t agree more.

I’m left with the image of a future golden eagle nest on Mount Diablo filled with two young golden eagle chicks, waiting for mom and dad golden eagle to return to the nest with a fresh ground squirrel to feed to them.

Only the parent eagles are off hunting in an area that has been poisoned in an attempt at ground squirrel “control” (AKA “eradication”).

Will the parent eagles be able to find a ground squirrel to feed their hungry chicks? I hope so. And I hope it isn’t poisoned …

We have to find a better way. /Gary

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16 Responses to “Poisoning Ground Squirrels — is it right?”

  1. Gerald Hill Says:

    It’s very true that ground squirrels are an important component of the natural ecosystem here in California; in fact, it’s the very prevalence of the California Ground Squirrel as prey that is responsible for central California having the highest population concentration of Golden Eagles anywhere in the world. Nevertheless, while their importance in the natural world can’t be denied, we also have to remember some of the less desirable side effects of a high rodent population: these creatures are carriers of some of the most dangerous contagious diseases, including Bubonic Plague. A field full of active ground squirrel burrows next to a children’s playground is simply not a good thing, any more than an abandoned house crawling with rats would be. Please, let’s use some hardheaded common sense here. Emotional responses simply confuse the issue.

  2. bhf Says:

    Thank you, Gary, for posting this story.

    As you know, we have been in a long struggle with the local cities and the county for a few years now to get them to reduce the use of poisons on wildlife, especially on the ground squirrel. This keystone species is necessary for the ecological system that exists in this county. They have been here for centuries living mostly in equilibrium with the other species. I hope that you can get some insightful input into the issues surrounding the conflict of ground squirrels inhabiting land that we have only recently started to live on.

    The stories that I have heard about the conflict of squirrels and humans are all very similar. Somebody buys a house along some open space with the hopes of having some healthy interactions with wildlife as they pass by. Somebody else moves a few houses down who likes the area for the piece and quiet. Before long, the person down the street starts to realize that there are wild animals that live in the open space. The ground squirrel, which is not much of a wanderer, starts to dig too close to the property line of this neighbor. Now we have a conflict with exaggerated stories of how the squirrels carry plague or almost bit one of their grand children.

    The first step is usually the Ag. Commissioner’s office is called. The Chief Deputy Ag. Commissioner comes out and recommends a control for the squirrels using poison. It doesn’t matter if other neighbors like the squirrels along their fence or rightfully have more tolerance for wildlife. Then, the commissioner sells the poison to one of five or so “poison guys” who come out to apply the poison. These “poison guys” are certified by the Ag. Commissioner’s office. Sometimes, they sell directly to the homeowner as well, depending on the situation. Then, the squirrels die and the complainant is usually happy.

    Well, ground squirrels don’t work this way. They have not live here for all this time to be wiped out by one stupid predator. The next year, they reproduce more offspring to make up for the difference. This is a common theme in ecological systems. So, now we have even a bigger conflict with the original complainant. This just cycles year after year.

    Why do we have the conflict in the first place? This should be the root of all our inquiries into this problem. The answer is complex and it has been hard to find a good answer to solving the problem in a socially acceptable manner. The easy answer is the reduced predator population due to human activity and our encroachment into wildlife refuge has fueled much of this conflict. Reduction of the predator population is itself complex as well. Obviously, besides being afraid of most predators and killing them off, we don’t provide a very attractive environment where predators would like to hang out to hunt for prey such as the ground squirrel. Basically, the ground squirrel lives near us under our protection. We clear the area of shrubs and grasses for fire protection, something they really like. We water our garden and give them lush plants to feed on. So, understanding the problem should lead us to a solution that can make most people happy.

    However, our attempts to show that there are solutions have been stopped. We think that simple modifications to the boundaries between our home and open space can help keep the ground squirrels in their place and limit the conflict that occurs. The solution may be costly. But, what is the true cost of controlling the ground squirrel using poison? The Solution will have to include letting predators come near your back yard. But, again, did the owners of these homes not want to live near wildlife?

    I encourage everyone to support the use of non-lethal or humane methods of control for these animals. Humans continue to mess up the fine balance that nature makes for itself and our fixes are usually as devastating. The conflict of ground squirrels is one that we can resolve with honor.

    Land for Urban Wildlife Inc.

  3. Tania Selden Says:

    Humans build their dream houses in wildlife habitat then poison the species they don’t want next to their property. That is wrong. Besides being inhumane, poisons wreck the ecosystem. Ground squirrels are part of Nature’s balance of prey and predator. The Contra Costa Department of Agriculture should pick up all the blue crystals one by one, then apologize. Kelly Adams wrote a magnificent letter. I am ready to dust off my civil rights signs and start marching for biodiversity.

  4. Gerald Hill Says:

    On the subject of ground squirrels: these plentiful creatures have a whole host of predators that depend on them to a greater or lesser extent. Badgers, coyotes, bobcats and various hawk and owl species have all been known to utilize these packets of protein for food. On one occasion earlier this year, I watched a very large great blue heron leave its (apparently unproductive) place in the shallows of a stockpond in Briones Regional Park and fly to an adjacent field where it stationed itself right in the middle of the ground squrrel burrows. There was nothing there that would seem very interesting except the naive squirrel youngsters that were just then exploring the surface. The herons don’t need to dismember their food. Just down the hatch!

    Nevertheless, a large ground squirrel population just dosn’t mix well with disease-wary humans that are always building their dwellings ever deeper into the fields and woods. Visible from within Briones Park are new homes being constructed on all sides. Are there any solutions besides feel-good antics painting a sign and marching around protesting the poisoning?

  5. Maggie Says:

    I am almost speechless at reading this! Of all the misguided actions, this one ranks high! Everyone else has already said it better than I could. My comment is that poisoning these ground squirrels means poisoning golden eagles which are a protected species (among others) – some group needs to file a lawsuit to stop this. Sadly that is often the only way to get results. Got any contacts at the Center for Biological Diversity? Barring that public outrage in the form of letters and showing up during public comment time at any meeting of the County Government or whatever entity is responsible for these actions is the way to go.

    Maggie Rufo
    Hungry Owl Project

  6. Maggie Says:

    Gary, you have made a difference! Myself and others are at work right now to protest this travesty. WildCare will be taking a stand and I hope you are touch with the director of Lindsay to also contact:

    Cathy Roybal
    Deputy Deputy–Contra Costa County dept of Agriculture
    2366A Stanwell Circle
    Concord, CA 94520
    925 646 5250

    to protest the use of this poison: Diphacinone.

    They will try to say it’s not harmful, but what they don’t tell you is that the “target” animals often eat MULTIPLE dose before they die or are preyed on and thus become a poison timebomb that can kill a raptor or a mammal! There is no safe anticoagulant out there that can be spread in the wild like that. NONE! Please everyone reading this send a letter or call to help put a stop to this! For more informaton on rodenticide poisoning:

  7. bhf Says:

    One solution may be to not let people live next to wildlife unless they sign a legal document saying that they know the wildlife is there and they are willing to live with them.

    Also, new home should be built in a way that limits wildlife conflicts. To get to this point, we would need a lot more cooperation among the developers and polititions to find what is acceptable construction techniques.

    Living with them means just that. Not destroying their habitat or natural ways. There are plenty of home within the city if anyone is afraid of wildlife.

    One last point about the emotional outcry about diseases; When was the last time you heard about disease comming from the ground squirrels? Let’s not be emotional. Rather, let’s use real logic and just say that many of us live with the ground squirrels without conflict. Why can’t those who don’t like wildlife just find a home somewhere else? Would you live in a home next to a train station if the trains woke you up all night?

  8. Maggie Says:

    Great points Bhf! Green building is all the rage but includes little-to-nothing about making projects safe for birds and other wildlife, including concerns about birds flying into windows, lighting, use of pesticides and rodenticides, etc. Recently here in Novato an office development has been approved in a degraded area of open space, but it abuts lots of wildlife habitat. I sent comments to the city planning commission stating that the developer should have as a condition of approval NOT to use pesticides or rodenticides, that they must only use integrated pest management. The developer agreed to tdo this. So all of us can pay attention to what’s going in with our communties and write letters about projects requesting that these things be part of the conditions of approval. I think also that any homes built next to open space must require that no cats or dogs be allowed to run loose outdoors.

  9. Glenda Says:

    Good Day Gary! Thank you for running this article. We live next to Buchannan Airport, with our two dogs. Our dogs always look forward to walking in the field (on leash) and hope to snag a squirrel or two, but they never do and we would never let them. Anyway, lately we noticed an eerie quite in that field and now we know why. All the ground squirrels have been eradicated by mindless humans. A couple of cats have also been noticed lying dead by the wayside, presumably having eaten a dead or dying squirrel. So who was it that said this poison wouldn’t affect other animals like dogs, cats, birds etc. ? What are these people going to go after next ? Tree squirrels, ducks and geese, feral cats ?? May the Good Lord protect all our animals and birds, because the way the world is going today we may not have many left for future mankind.

  10. Diana Says:

    Just another example of humans thinking they are so much more important than any other species on the planet (personally, I place homo sapiens in the same category as cockroaches or any other noxious pest). Poisons for ground-burrowing rodents are a short-term fix at best; toxic fumigants are a little more effective, plus they leave no poisonous residue in the animal’s body, but not for ground squirrels, since their runs can sometimes go to 26-28 feet below the surface, unlike gophers and moles, which stay closer to ground level.

    There are three solutions to the ground-rodent “problem”: the first is physical barriers, gopher fencing, lining planting beds with hardware cloth before filling them with soil and plants. The second is removing the food source by re-landscaping/hardscaping (in the case of gophers and ground squirrels) or eliminating lawn grubs, a major food source for both moles and raccoons (yeah, I know, this involves a pesticide). The third solution is – DON’T MOVE INTO AN AREA WITH A LARGE WILDLIFE POPULATION!! Try a third-floor condo in the downtown area of a larger city, and quitcher bitchin’!

    Personally, I think this planet would be a far, far better place with half as many humans and twice as many critters.

  11. Helene Says:

    Thank you Diane for you support of more wildlife freedom. I have found that my third and fourth story condo gives me a lot of wildlife next to it. This is because I live next to an oak grove which is next to Grayson Creek. We get all kinds of wildlife. I protect this area, which is part of the Association, by not allowing any killing or disturbance here. So far it has worked and there are no conflicts. We do not have ground squirrels here, though.

    Our group has tried hard to get the Ag. Commissioner to fund a study to show that barriers and planting alterations could work. We were turned down and basically swept under the carpet. We did not have enough support at the time. Their point was that simply it would not work and even if it did, they felt the poisons were the best option. I can only think that there is a wall that is deep enough and tall enough to keep out any animal. Even if a ground squirrel did make around a wall, a simple live trap would work. The problem with live traps is that you cannot relocate the animal. But, if you leave enough space on the other side of the wall, then it would not be considered relocation to release it there. I am also equally sure there are plants that can resist ground squirrels or ones that they simply do not like.

    I would like to see more habitat built, rather than complete exclusion, though. Leaving enough space for wildlife with a wildlife friendly barrier works best for me. Build-up the open space with natives and let the wildlife flourish. Next to my condo is a non-stop wildlife show.

    You can help support our group by contacting the e-mail at bhf above.

  12. Lola Hutchinson Says:

    They were there before the homes, Let them be. besides they can be a lot of fun to watch.

  13. Jacquie Wood Says:

    Humans have become so ignorant and arrogant that we as a species have the strange idea that we are somehow seperate from the rest of Creation. If one truly believes that All was created by Creator of All That Is, how does one reconcile erradicating what Creator decided was neccessary for our planet with our momentary inconvenience? In the history of our planet we are the “cancer”, the parasite consuming all the resources that were put in place by Creator to sustain life on this planet! As a species we are the most destructive, and the species with the greatest ability to stop the destruction/pollution of our planet and find long term solutions to the poisons in thought, belief, and attitude that have enslaved us as a species for so many centuries. Wake Up People! There is no natural law to prevent the extinction of humans, if we destroy our fellow creatures, plants, insects, fish, birds, (you name it) we will finally destroy ourselves. The laugh is….Life will go on just fine without humans…Creator will continue to create, the world will continue to spin….just without us!
    Be Blessed with new solutions, new beliefs, new directions for our human inventiveness!

  14. bhf Says:

    Make a difference. Join us this Weds., Dec. 3 at 7pm to discuss how we can make a difference and change the practice of poison first. The meeting will be in Pleasant Hill, 100 Gregory Lane. We will have a couple of presentations and a discussion on the subject. Write to me at for more details.

    I look forward to a meeting a lot of new concerned citizens.

  15. Land for Urban wildlife meeting « Bay Area Wildlife Blog Says:

    […] -right/#comments […]

  16. Lisa Park Says:

    I am an animal lover and that includes ground squirrels. As a horse owner, I recognize the danger that an over-population of ground squirrels can cause. There is an environmental solution to poisoning and it is much more effective than trapping. The Burrow Blocker machine ( fills the ground squirrel holes with a mixture of sand and water. There are no more hazardous holes and the ground squirrels are trapped inside or move on to find a new hole. It has worked great at my ranch and I don’t have to worry about my other animals or wildlife.

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