It took a lot of heavy lifting, three transport vehicles, and a few mugs of hot cocoa from a nearby resident to keep warm and motivated.

But after many hours of coordinated efforts, dozens of volunteers and staff from the International Fund for Animal Welfare rescued 10 Risso’s dolphins that had become stranded in Wellfleet Harbor on New Year’s Day.

Kerry Branon, a spokeswoman for the nonprofit animal welfare group, said calls from residents that three dolphins were swimming in the harbor first came in around 8 a.m. By the time crews arrived a few hours later, they determined that there was a total of 10 Risso’s in the area.

She said the dolphins may have come close to shore while trying to capture prey.

Three of the same dolphins restranded in Truro on Monday, before being rescued and later released at Herring Cove in Provincetown.

On Sunday, rescuers at first spent several hours trying to herd the dolphins toward the open seas using two boats, said Branon. But as the tide went out, the stubborn marine animals became stuck in a part of the harbor called Chipman’s Cove.

“So we went with plan B,’’ Branon said. “And it was all hands on deck.’’

Rescue teams braved cold and biting winds as they trudged through the thick mud in the harbor to safely move the dolphins, one-by-one. The marine animals were placed on stretchers, and then wheeled using special carts to the three nearby transport trucks — a flatbed that could fit two of the dolphins, and two enclosed vehicles that could each hold four of the marine animals.

Crews were familiar with the territory. In September, the group rescued 16 Atlantic white-sided dolphins that had stranded in a cove near Chequessett Neck Road.

Risso’s, which are protected under the Marine Mammal Protection Act, are not an endangered species, according to the National Marine Fisheries Service. They are sometimes called “gray dolphins’’ because of their light coloration, and can weigh 660 to 1,100 pounds, according to the federal agency.

Branon said it took 15 people to move from the mud flats to the vehicles some of the larger dolphins.

“They are pretty big, and really quite heavy,’’ she said, adding that this was the largest stranding of Risso’s the nonprofit has ever responded to. “It’s a massive undertaking, 10 dolphins.’’

Once the Risso’s were placed inside the transport vehicles, they were driven to Corn Hill Beach in nearby Truro. The dolphins were taken there after the group determined the favorable winds and tides would help the animals make it back out to sea, Branon said.

Branon said staff and volunteers from the group, as well as curious residents who happened upon the scene and local police all contributed to the successful rescue mission.

“It was an amazing team effort over many, many hours on a blustery, cold winter day,’’ she said. “Everyone was doing everything they could to save those dolphins. . . . I even saw a guy on the side of the road in Wellfleet, and he was standing there with a tray of hot cocoa. He had fresh mugs of cocoa that he made for everyone.’’

Steve Annear can be reached at steve.annear@globe.com. Follow him on Twitter @steveannear.