Burrow Modification | California Ground Squirrel

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Squirrel burrows can be extensive. Modification of these systems may temporarily deter activity, but additional control efforts are usually required to prevent the ground squirrels from returning. This makes burrow modification less effective than alternative control methods, but it may have utility in some situations and can be useful when implemented with other management practices. 

In urban areas, burrow destruction is often impractical because the entire area must be ripped to a depth of at least 20 inches. This is difficult to achieve without heavy machinery.

Options for burrow modification include:

• Burrow exploder
  A burrow exploder uses the force from the ignition of a gaseous mixture of propane and oxygen to create a concussive blast. It is less effective than most baiting and fumigation options and also requires a lot of equipment, including personal safety gear (hard hat, heavy gloves, safety glasses, ear plugs, ear protectors, and full body protective clothing), a fire extinguisher and shovels (highly recommended),  and 50-foot hoses that feed the gases into the nozzle. Depending on the size of the gas canisters that you use, you may need a hand truck, ATV, or a vehicle to carry the equipment. Initial tests have not indicated this to be an effective removal approach (around 30-35% success rate), although destruction of burrow systems may have utility in some situations. 
• Deep ripping
  Deep ripping can be used to substantially slow the reinvasion of California ground squirrels once they have already been controlled in an area. However, destroying the burrow entrances without effectively controlling the ground squirrel population by other management methods significantly reduces the effectiveness of deep ripping. 
  This method is generally unsuitable in areas that have large rocks or boulders or in orchards, where burrows are adjacent to trees. Deep ripping should reach a depth of at least 20 inches, or more if possible. Studies have shown that destruction of burrows at a depth of 12 inches did not result in a reduction in colonization time. One to three ripping shanks mounted on the hydraulic implement bar of a tractor works well. Space shanks approximately 3 feet apart. 
• Burrow Blocker
  The Burrow Blocker system is a relatively new product. The system pumps a slurry of water and sand into ground squirrel burrows. The water is then absorbed into the soil and leaves the sand in the burrow, filling those portions of the burrow system into which the slurry can flow by gravity, thus trapping the ground squirrels underground. Research is needed to determine the efficacy of this product.

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