Over the past two decades, the Antelope Island mouflon has provided animals that have restored herds in the mountain ranges of the western Utah Desert. The isolation of the flock, which protected it from deadly pathogens carried by their domestic cousins, was at the heart of this success.

But the rams started falling dead last November. Biologists in the Wildlife Division of Utah know this because they equipped 10 with telemetry collars last year. Since then they have learned that a respiratory illness had killed them, as well as most of the other 150 sheep in the area.

The 26 survivors, identified during a flyby on Wednesday, must be killed so that another flock of "Rocky Mountain" bighorns can be relocated to the largest island in the Great Salt Lake, according to Jace Taylor, a biologist. of the DWR.

The amazing news was announced Thursday at the end of the Utah Wildlife Board meeting, when Taylor asked council to cancel the two coveted tags issued each year to allow hunters to hunt sheep on the island.

"It's not something for which we can vaccinate. We need to depopulate the herd and start again, "said Taylor. "It's sad."

This demise illustrates the vulnerability of wild sheep in the West and the difficulty of managing this emblematic species of big game in the presence of sheep and goats. But Antelope Island does not contain domesticated animals, so the source of the disease is a mystery, according to DWR spokesman Mark Hadley.

On Wednesday, biologists made a thorough study of the island, flying low. They counted 20 ewes, four rams and two lambs, Taylor said on the blackboard, displaying gruesome images of scenes of rotting sheep carcasses on a screen.

It is a sad end for a population that has provided 250 sheep for translocations that have been herds in the Deep Creek, Oak Creek and Stansbury ranges, resulting in 127 permits for an animal that few hunters can legally hunt. Just over a year ago, 40 animals were captured and transferred to the Oak Creek and Stansbury mountains after being tested in good health, Hadley said.

(AP Photo / Rick Bowmer) Officials from the Utah Wildlife and Parks Division used a helicopter to transport the bighorn sheep to a rest area on the island. 39, Antelope Island, where he was vaccinated and subjected to health checks before being shipped to the Stansbury and Oak Creek mountains. The flock of the island has provided many sheep to repopulate the mountain ranges of the western desert, but a recent epidemic has decimated the herd. Survivors must be killed by air hunters this month and replaced by disease-free animals.

The Bighorns were once abundant throughout Utah, but after the arrival of the Mormon pioneers, they disappeared from disease and overhunting. After a translocation program launched in 1973, they returned to some of their native rangesbut the sheep remains a rare and sought after big game.

Desert bighorn sheep occupy southern Utah, while the northern half of the state is home to dozens of Rocky Mountain stockmen and their Californian subspecies. Antelope Island is home to California sheep.

DWR recently picked a sick flock. To prevent the spread of the disease, wild sheep disappeared from Mount Goslin in 2009, just east of Flaming Gorge, according to the agency. sheep management plan.

In the mid-1990s, the state sent desert spines into Zion National Park, where they had been eliminated decades earlier. This transfer has been so successful that the National Parks Service is now take out dozens of sheep from Sion avoid the same disaster that hit the Antelope Island herd.

Zion's flock is now so important that officials are worried that some rams will get lost in search of an unoccupied habitat and come back after being in contact with domestic sheep carrying a deadly germ.

Such a scenario could have occurred at Antelope Island.

"The [Great Salt] The lake is so low that there is a link to the mainland at the southern end of the island and the causeway at the north end, Taylor said. "In theory, an animal could have left the island and come back. We may never know it, but we will take steps to prevent it from happening in the future. "

One of these steps is not good: taken in helicopters, the snipers of DWR or the US Department of Agriculture will target the survivors in the air. This is the case if there are more at the time a plan is developed. DWR wants to restore a flock of nurseries to the island as soon as possible and it does not require sheep to stay, Taylor said.

"We would like this to happen in a few weeks," said Hadley. "You have to not only do it, but also avoid suffering. It is a slow and painful way. Deadly elimination is a much more humane way. "

The authorities say allowing hunters on the island to bag the rest of the sheep is not a viable option, even if hundreds of people would pay for it. They intend to recover any usable meat.

The Antelope Island herd was established in 1997 with 29 animals and showed no signs of trouble until November, when some of the collared rams stopped wandering. Biologists have investigated stationary telemetry signals and have witnessed a disturbing spectacle.

"We found a lot of dead mouflons. A number of unhealthy, emaciated animals had problems walking, "said Taylor at the Wildlife Board. They took mucus samples and sent them to a laboratory. A month later, they came back HIV positive for a strain of pneumonia.

The results of the laboratory sealed the fate of the herd. After the removal of the survivors, DWR hopes to bring new animals this year. However, it may take years before this herd can be hunted or exploited for future translocations.

"We have to make sure we do not run out of animals," said Taylor. "It must be a clean flock. Our bighorn sheep program is based on these nursery herds. "

The Antelope Island sheep may be doomed, but their genes remain in the western desert herds, which will soon provide the animals that will restore a population to the most famous island of the island. ;Utah.