The volunteers paid their own airfares, board and transport costs in an expedition organised by the non-profit conservation organisation Earthwatch Institute.
Mr Mahoney became involved because he had an interest in wildlife, especially cats.
As well as farm work, like feeding animals and mucking out their enclosures, the group helped in the farm's vet clinic and looked through photographs taken by motion-sensing cameras set up to film wildlife.
It was a working farm, stocked by cattle and goats that mingled with native animals in the desert environment. Wild animals included cheetahs, giraffes, zebras, porcupines, hyenas and baboons.
Cheetahs would not attack cattle because they were too big. They would also steer clear of a person carrying a big stick, Mr Mahoney said.
They did attack goats, but those at the farm were protected by dogs bred to live with them and to see off any predators. Having them allowed wild animals to co-exist with farming.
Elandsvreugde also supplied the dogs, called Anatolian shepherds, to other farms. There was a two-year waiting list for them.
"Any animals that will not harm a farmer's dog are not likely to get shot. Otherwise [farmers] are allowed to shoot wild animals on their property," Mr Mahoney said. Cheetahs were not the most dangerous wild animals in Namibia, he said. That honour belonged to baboons.
"Get too close to them and they will attack a person. One of the dogs at the vet clinic had been attacked by a baboon and lost part of its leg. The baboon was on its own, and that's the reason why the dog actually survived."
Hyenas could also be scary when they came out at night.
Even cleaning out the goat pens could have its problems, Mr Mahoney said.
"Sometimes they would try and eat your clothes or hair, push people out of the way or jump up into the wheelbarrows."
The farm also hosts tourists, and keeps hand-reared and semi-tame cheetahs in a large enclosure for them to see. Being allowed inside it with trained staff was a thrill for Mr Mahoney, who found there was no need to be scared.
"They just acted like big, overgrown domestic cats."