A border collie named Ron recently helped the park district solve what could have become a costly problem.

When crews left the site of the Vashon Fields project last month — abandoning the site for the winter to let the newly planted sports fields grow — a new group almost immediately moved in. A flock of Canada geese came to feed on the over 5 acres fresh fields, tearing up grass and leaving behind destructive droppings.

Ron Krieger, the athletic fields groundskeeper, said that although geese are normally not a concern to the park district, the birds could kill this particular grass because it is young and fragile.

“The hungry geese can cause severe damage to the delicate new fields as they pull up the grass by those shallow roots,” he said.

After a couple of unsuccessful attempts at keeping the geese away, Krieger remembered he had seen wooden cutouts of dogs used to advertise the Vashon Sheepdog Classic in September. He approached organizers of the sheepdog trials, hoping the cutouts might trick the birds into staying away.

Maggi McClure, a sheepdog trainer who heads the Sheepdog Classic each year, told Krieger she would do him one better. Last week she brought one of her border collies to the field.

Under whistle command, Ron, a 2-year-old sheepdog in training, ran in a large loop around the field, immediately scaring off the geese.

McClure said that Ron was actually looking for sheep, as he is trained to do, and probably didn’t even notice the birds.

“These geese pretty much took off, and he was still looking for sheep,” she said with a laugh. “He was a little deflated, but he got the job done.”

Though it was Ron’s first experience with geese, McClure said it’s very common for sheepdogs to be used to keep the pesky birds away from parks, golf courses and sports fields.

Park district employees also installed three black dog cutouts at the fields, hoping to remind the geese of the border collie and fool them into staying away.

Susan McCabe, program coordinator for the park district, said that so far it seems to be working. No one has reporting seeing geese at the field in a over week. She said the park district is thrilled to have found a free and humane way to save the new athletic fields from the hungry birds.

“It would have been a huge bill to replace the grass, and they were already tearing a lot of it up,” she said.

McClure, for her part, says she’ll bring her dog back again if the geese return. She’s glad to help in the effort, she said, as she has a 9-year-old son who plays sports and will one day use the new fields.

“I can’t wait to see my son running out there instead of my dog,” she said.