Ground Squirrel Invasion - Ask Extension
We are fighting a ground squirrel invasion around our quasi-rural Sherwood home. They are digging around our foundation, have gotten into the garage ...
Knowledgebase
Ground Squirrel Invasion #874515
Asked June 24, 2024, 5:40 PM EDT
We are fighting a ground squirrel invasion around our quasi-rural Sherwood home. They are digging around our foundation, have gotten into the garage and torn apart insulation and chewed through wires of our garage door opener, and are digging throughout the garden and grass, making holes that are creating a risk of tripping/twisting an ankle. We have someone coming to trap and kill them but I know that this will quickly become cost-prohibitive. Given that they are non-native and invasive, is there anything else we can do to fight this battle? This year the problem is much worse than past years, indicating that they're quickly reproducing.
Washington County Oregon
Expert Response
Hello - First, I'd be interested in knowing where the "non-native, invasive" information was sourced. There are no non-native, invasive species of ground squirrels in the U.S. We (OR and U.S. broadly) certainly have multiple ground squirrel species, and they are rodents and reproduce at rates typical to that group of animals, but they're native. Therefore, your yard is occupied and supporting successful survival and reproduction by fulfilling (or excelling at!) the habitat requirements for that particular species.
Have you identified which species of ground squirrel they are? That would be very helpful in using knowledge of their species-specific ecology (e.g., breeding season, seasonal estivation or hibernation cycles, seasonal diets, etc.) to help target your management.
In the near-term, saving your home's foundation is an obvious first priority. For reliable and trustworthy expertise on that, I would consult a licensed building contractor with a successful background and references on shoring up/saving foundations in the presence of shifting fill or in this case, tunneling animals. I expect they might recommend trenching 2-3' around the perimeter and then installing either corrugated metal or lining the trench with welded wire and filling with coarse gravel, but getting professional/structural expertise would be paramount importance.
You are right to be concerned that trapping alone won't be enough, and/but, realize that monitoring and lethal population reduction will be an ongoing task over time - unless you can implement complete exclusion (above-&belowground "fence"/barrier around your property perimeter). In the meantime, if you're already paying a licensed and trained wildlife control operator who holds a pesticide applicator license, you might ask them about toxic baits, applied in-burrow to reduce risks of non-target injury or mortality, to be a less labor-cost-intensive option. The rodenticides licensed for most burrowing, prolific rodents are registered and restricted, and thus require an OR Dept of Ag pesticide applicator's license. There ARE unrestricted gas bombs available for use by non-commercial (i.e., DIY) people, but be EXTREMELY careful if you (or your contractor) use any gas - restricted or not. I'm actually amazed that any lethal gas bomb is allowed for potential residential-area use. There are tragic cases in which burrow openings near or beneath a house or near its air intakes have allowed poison gas to enter living spaces and kill people and pets. So please be very cautious in considering that option.
Happy to help with species ID if you'd like to return here and post in some pictures of holes and animals.
Have you identified which species of ground squirrel they are? That would be very helpful in using knowledge of their species-specific ecology (e.g., breeding season, seasonal estivation or hibernation cycles, seasonal diets, etc.) to help target your management.
In the near-term, saving your home's foundation is an obvious first priority. For reliable and trustworthy expertise on that, I would consult a licensed building contractor with a successful background and references on shoring up/saving foundations in the presence of shifting fill or in this case, tunneling animals. I expect they might recommend trenching 2-3' around the perimeter and then installing either corrugated metal or lining the trench with welded wire and filling with coarse gravel, but getting professional/structural expertise would be paramount importance.
You are right to be concerned that trapping alone won't be enough, and/but, realize that monitoring and lethal population reduction will be an ongoing task over time - unless you can implement complete exclusion (above-&belowground "fence"/barrier around your property perimeter). In the meantime, if you're already paying a licensed and trained wildlife control operator who holds a pesticide applicator license, you might ask them about toxic baits, applied in-burrow to reduce risks of non-target injury or mortality, to be a less labor-cost-intensive option. The rodenticides licensed for most burrowing, prolific rodents are registered and restricted, and thus require an OR Dept of Ag pesticide applicator's license. There ARE unrestricted gas bombs available for use by non-commercial (i.e., DIY) people, but be EXTREMELY careful if you (or your contractor) use any gas - restricted or not. I'm actually amazed that any lethal gas bomb is allowed for potential residential-area use. There are tragic cases in which burrow openings near or beneath a house or near its air intakes have allowed poison gas to enter living spaces and kill people and pets. So please be very cautious in considering that option.
Happy to help with species ID if you'd like to return here and post in some pictures of holes and animals.
