Deer can swim, but not very far. When they showed up for the first time on Hawaii island, mystified residents wondered how they got there.

The island is some 30 miles southeast of Maui, where deer are plentiful.

Hawaii wildlife authorities think someone dropped a few from a helicopter on the northern tip of the island. And tracks along the southern coast indicate deer were pushed into the ocean from a boat and forced to paddle ashore.

Wildlife managers want to eradicate them to avoid a repeat of the destruction seen on other islands, where they have eaten through vineyards, avocado farms and forests where endangered species live.

Officials estimate there are 100 deer on the northern and southern ends of Hawaii island. A government-funded group is leading efforts to get rid of them before they breed.

"They didn’t get here by themselves, so the people who brought them over did so and have done it many times," said Jan Schipper, the group’s project manager.

People have reported seeing deer on Hawaii island for a while, but it wasn’t until a motion-sensor camera captured a photo of one last year that their presence was confirmed.

Axis deer, called chital in their native India, are similar in size to whitetail deer found in the continental U.S. Tigers and leopards keep axis deer numbers reasonable in India, but the deer population is growing 20 percent to 30 percent per year in Hawaii because there aren’t any natural predators — except for humans.

The deer first came to Hawaii in the 1860s as a gift from Hong Kong to the monarch who ruled at the time, King Kamehameha V. They were first taken to Molokai.

In the 1950s, some deer were taken to Maui as part of post-World War II efforts to introduce mammals to different places and increase hunting opportunities for veterans, said Steven Hess, wildlife biologist with the U.S. Geological Survey. Biologists believed they could improve the environment by introducing species that didn’t naturally exist, he said.

The experiment has had devastating, unforeseen consequences in Hawaii, where plants and animals evolved in isolation over millions of years and lack natural defenses against introduced species.

On Maui, deer have caused $1 million in damage during the past two years for farmers, ranchers and resorts, according to a county survey. They spent half that amount during the same time trying to eradicate the animals. On Lanai, deer that eat everything from Hawaii’s native ebony tree, the lama, to a native olive tree and a now-extinct mint helped turn a rich native forest into a desert-like landscape so desolate people compare it to the moon.

Hawaii island hunters like Tony Sylvester welcome the axis deer as a new source of meat.

There are no native land mammals in Hawaii except for a bat. Hawaii island hunters, who hunt to supplement their diet, say the deer should stay because the gift to the former king was for all of Hawaii.

Sylvester suspects other hunters brought the deer from nearby islands to retaliate against government agencies and conservationists for converting vast tracts of hunting ground to forest restoration. He said he understands the concern for the environment and the need to protect the forest, but he said the deer can coexist if managed properly.

"Before you know it, everywhere is a pristine area and it’s more and it’s more and it’s more," he said. "And our culture is slowly getting pushed away and pushed out."

Officials have fenced off forests and killed sheep, goats and pigs inside the area to help save a multitude of species, such as the slow-growing mamane tree and the palila songbirds that eat its seeds.

The Pele Defense Fund, a group that led a successful legal fight in the 1990s to win Native Hawaiians access to private land for hunting, is now rallying hunters together for a class-action lawsuit against the state to stop its efforts to eradicate game animals and fence off land.

"They go in and kill all the pigs and everything else. Then you eliminated the hunter," said Palikapu Dedman, the fund’s president. "I think the hunter has been ignored and it’s the state’s responsibility to look out for them, too."

Jimmy Gomes, operations manager at Ulupalakua Ranch, spanning 18,000 acres on the slopes of Maui’s Haleakala volcano, said deer have been jumping over rock walls and through wire fences to eat ranch grass set aside for cattle. Gomes said he’s seen a thousand at a time, and has had to wait several minutes for a herd of deer to pass before he can ride through on horseback.

"Sometimes you’re driving cattle, you’re moving cattle across, and all of the sudden you see this — like the mountains moving — this deer coming down," he said.

Gun club members and ranch employees have killed more than 1,000 deer on the ranch this year, but Gomes said it hasn’t made a dent in their numbers.

Sam Ohu Gon III, senior scientist and cultural adviser at the Nature Conservancy of Hawaii, said the deer could threaten Hawaii island plants that are important for the environment and Hawaiian culture. Among those are the uhiuhi tree, which has a hard wood ancient Hawaiians favored for making weapons and tools, and the ohelo berry, which is used to make jam and is sacred to Pele, the goddess of volcanoes.

The threat to Hawaii island’s native ecosystems is particularly serious as half the island still has native vegetation — a high ratio compared with other Hawaiian islands.

"It cannot be a free-for-all of hunting everywhere you want and the hell with everything else. Because what would that result in? That just spirals us down into less and less of what makes Hawaii unique," Gon said.