His job is a wild goose chase.

Max, a 5-year-old border collie, is in charge of keeping 172-acre Governors Island goose free. The birds are a major nuisance, with each eating several pounds of plants and leaving up to a pound of droppings each day.

“We had so many complaints about the goose waste . . . It’s gross,” said Jim Reed, director of park and public space for the Trust for Governors Island. “They decimated the new sports field over the winter. They just ate it down to the ground.”

Officials “tried everything” to discourage the geese, Reed said, including flying model planes and shining lasers, but the only thing that seems to work is a dog patrol.

They found Max in January through Maryland’s Mid-Atlantic Border Collie Rescue after a dog trainer steered Reed to the breed.

While other breeds nip at their flocks, border collies take a softer approach to herding, making them well suited for Canada geese, which are federally protected and must be treated humanely.

Max is on the move from 4:30 a.m., when he rouses Reed with a wet nose to the ear in their Central Park South apartment.

The duo hits the island by 7 a.m. for the first of Max’s four, 40-minute patrols of the day. They walk the island in search of the birds, who sometimes scatter at the sight of the dog.

When they spot the feathered pests, Reed gives the command and Max sprints around the flock, staying low “like a prowling wolf.”

He doesn’t bark or bare teeth, but the geese “want nothing to do with him” and take off, Reed said.

He follows, turning left or right at Reed’s command, as the birds fly away out to the harbor.

When not on patrol, Max relaxes under Reed’s desk or hops into the golf cart to greet the crowds. He remains on a leash, sporting his “Working Dog” vest whenever the island is open to the public.

He’s the only dog allowed on the island.

The pair stay until 6 p.m. to shoo a “super flock” that flies in from New Jersey each night.

At least 500 geese visit the ­island May through September, and thousands descend on it in the fall and spring.

Max is essentially a volunteer, though the Governors Island trust covered his adoption and training costs and pays his medical bills.

“We talked about a stipend, but instead we are going to fund-raise for Mid-Atlantic Border Collie Rescue to ensure more great dogs like Max find homes,” Reed said.

“He gets a lot of satisfaction if he has a job to do. He has a hard time with days off.”

Off duty, Max is business-like.

“He doesn’t do tug-of-war; he doesn’t do fetch,” Reed said. “Because he was a farm dog, he doesn’t really seem interested in other dogs, and he doesn’t really play.”

He does enjoy playing fetch with a Frisbee fetch, herding squirrels and cuddling up on the couch.

“He’s the first dog I’ve ever allowed on the sofa,” Reed said. “He works so hard all day, I can’t imagine not letting him.”