Web Exclusive - August 2013
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Handling Burrowers on the Golf Course

By Del Williams

When tasked with keeping fairways, greens and grounds in meticulous shape for golf match play, tournaments or club members, burrowing rodents such as gophers and ground squirrels can be a groundskeeper's worst nightmare. Suddenly, unsightly, dug-up mounds of earth are everywhere. Turf, plants, flowers and trees are being damaged or killed off. Holes and shallow tunnels are just waiting for someone to step in them and trip, or wreck a golf cart, lawnmower or other equipment. For groundskeepers tending golf course turf and facilities, burrowing rodents can quickly become Public Enemy No. 1, costing many thousands of dollars of damage.

"We wanted to keep our golf course and range turf flat, smooth and playable, but burrowing prairie dogs and ground squirrels made this very difficult," said Kelly Walker, a mechanic involved with grounds maintenance at Dinaland Golf Course, a public 18-hole regulation length course with a 20-tee driving range in Vernal, Utah. "Hundreds of prairie dogs had taken over our re-seeded driving range, and were starting to invade our golf course, where ground squirrels were also a problem. We'd replaced our range picker—it broke down running over mounds and falling into softball-size holes while picking up range balls. We were losing a lot of range balls down these holes, and could not let the prairie dogs continue to tear up our new turf.

"The ground squirrels left holes and mounds along tees, fairways, landscaping and flower beds," Walker added. "When golf carts ran into these holes or mounds, their steering needed repair. The squirrels dug up rocks, which chipped and bent our reel mowers, requiring time-consuming repair, sharpening or replacement. They chewed through irrigation wiring, leaving brown spots in the turf where a line of sprinklers wasn't turning on. You don't know how much damage burrowing rodents can do to a golf facility until you need to fix it."

While golf groundskeepers have traditionally relied on poisons or traps to combat burrowing rodents, increasingly the public, as well as club members, are asking that this be done with the safest non-chemical means possible. Proactive grounds maintenance professionals are also seeking greener, more effective means of eliminating burrowing pests to minimize grounds damage and labor cost, as well as the risk and liability of handling poisons and traps in inhabited areas.

Use of Poisons/Traps

The challenge for golf course groundskeepers and maintenance crews is that poisons—the most common solution to address the problem for the past hundred years—are becoming increasingly unusable due to environmental, regulatory and safety issues. These poisons come in varying forms, the most common being baited food, which carries inherent risks even if applied properly.

"We tried putting poison bait and gas bombs down the holes and covering them up, but found them ineffective," Walker said. "We'd come back and find the burrowing rodents had thrown the poison bait and gas bombs out of their holes. To enhance public safety and reduce poison risk, we sought a more effective, chemical-free approach."

Ironically, a major hazard occurs when the poison is effective—the dead rodent attracts other predators, who themselves will be poisoned.

"With poisons, there's always a danger of secondary kill-off if dogs, cats, birds of prey or other wildlife eat a poisoned rodent carcass," Walker said. "When possible, it's far better to minimize any poisons or chemicals used."

Poison can also take the form of gas. Over the years, a common gopher poison is Fumitoxin, placed underground. For the gas to be contained, the moisture content in the earth must be at a certain level. If not, the gas escapes through cracks, does nothing to handle the burrowing rodent problem, and can be harmful to humans. Fumatoxin contains aluminum phosphide, a dangerous Federal-Restricted-Use pesticide. Obviously, in a heavily used area, poisonous gasses are a health hazard to be avoided.

Other common pest control methods can often prove impractical.

"Trapping didn't work because there were so many burrowing rodents," Walker said. "I'd try to set and cover the traps by 6 a.m., before the public arrives, but could not check the traps throughout the day because I have so many other things to do. Once the rodents go down their holes, they're unreachable by shooting."

"A big drawback of most pest control methods is that they leave the tunnel systems of burrowing rodents open to invading animals," Walker cautioned. "Unless you collapse these tunnel systems, it's easy for burrowing rodents from neighboring properties to move in and multiply."

Non-Chemical Solution

Those working to eradicate burrowing rodents in golf course facilities without poisons or other harmful chemicals are instead finding success with a poison-free, non-chemical, pest control method that delivers a precision underground shockwave to the targeted animals while also collapsing their tunnel systems to prevent re-infestation.

"With the Rodenator system, we eliminated the prairie dog problem and much of the ground squirrel problem within the first month," Walker said. "We have the burrowing rodent problem under control. We're saving about 30 hours a week in burrowing rodent-related labor and grounds-equipment repair. We avoid costly, labor-intensive poison baiting and trapping. Overall, we could save tens of thousands of dollars over the next several years in repair, maintenance, and labor costs. The grounds are shaping up, which makes for better, safer, faster play, and happier golfers."

This pest elimination system, developed by Meyer Industries, uses a wand inserted into a burrow hole, and a mixture of oxygen and propane gas is shot into the hole for typically 60 to 90 seconds, depending on the type of animal. Then another button on the wand is pressed, igniting a spark into the mixture, creating a precision underground shockwave. The shockwave instantly kills the burrowing rodent while also destroying the tunnel. Although it has drawn some complaints by PETA, the American Veterinary Medical Association considers death by concussion with sufficient force to be "a humane method of euthanasia."

"There's an immediate reduction in mound and hole digging activity, which shows the system's effectiveness," Walker said. "Ongoing monitoring and maintenance of golf facilities is still needed due to their size, and the possibility of burrowing rodents coming in from neighboring properties."

Because the mixture is consumed immediately and completely, it leaves no chemical residue behind. In one fell swoop, the animals are extinguished and the tunnel system local to the hole is collapsed. This eliminates handling and disposal of the carcass, and prevents re-infestation of the tunnels by neighboring rodents.

In a golf course, the turf's root system holds the top of the ground together so detonation of the gas and collapse of the tunnel system causes little, if any, grounds damage. Occasionally, the collapse of the tunnel system will part a small section of turf near the surface. But the groundskeeper can control the extent of this by how much gas is injected. Since the groundskeeper is right there controlling and monitoring the process, he can quickly smooth out any parting of the turf, which quickly grows back.

"For us, there was very minimal turf repair needed when using the system, except for filling in the rodent hole, which we would've done anyway," Walker said.

Del Williams is a technical writer based in Torrance, Calif. For more information, visit www.rodenator.com.