ANTELOPE ISLAND STATE PARK -- At first, Dave didn't seem very pleased to be stuck in a trailer. The mature bighorn sheep slammed his thick, curled horns into the side of the metal enclosure, creating a loud banging sound that rang out across the open field.
He soon calmed down, however, and grudgingly accepted his new surroundings. After flying through the air for several minutes, perhaps he was just glad to be back on his feet.
Dave (someone had written "My name is Dave" on his right horn) was one of several bighorn sheep on Antelope Island that were captured Tuesday as part of a relocation effort that will help maintain a sustainable population of the mammals on the island, as well as establish a new population in another part of Utah.
A helicopter flies into the island's mountains, where a crew locates and captures the animals, puts them in a specially designed sling and transports them back to a staging area for examination.
The animals are not sedated, but are blindfolded and have their legs tied together to minimize the stress of the journey and allow people to safely examine and move them.
State wildlife officials hope to capture 30 bighorns, a mix of young and mature rams and ewes, by today's end. The sheep will be transported in trailers and released in the mountains east of Oak City in central Utah, where bighorns have naturally occurred in the past but currently aren't found.
Steven Bates, wildlife manager at Antelope Island State Park, said the island is equipped to sustain a population of 150 bighorns. However, a high reproductive success rate in recent years has grown the population to 180.
"We have more than 500 bison, 200 antelope and 800 deer on the island, in addition to the sheep, so there are a lot of mouths to feed," Bates said. "It's important to keep the population within our established objective."
Bighorn sheep are native to Utah but were nearly wiped out in the state by the 1960s due to a variety of factors. They were reintroduced to Antelope Island in 1998, when 23 were brought in from Canada. Six more from Nevada were released in 2000, and the population has thrived ever since.
This week's capture and relocation effort was the fourth since reintroduction. In total, Bates said, about 150 bighorns have been moved from the island to suitable habitat in other parts of the state.
"It's been real good for the sheep here," he said. "They do extremely well out here and produce lots of lambs."
The effort is mainly focused on capturing ewes, but a few bucks are needed as well to allow for natural reproduction on their new range.
Once the sheep reach the staging area, they are weighed and measured, given blood tests to check for diseases, swabbed for bacteria, and given antibiotics and worming medication before being loaded into the trailers.
They are also fitted with radio collars so officials can track their movements.
Dozens of people are involved, including employees from the Utah Division of Wildlife Resources and volunteers from local sportsmen's groups.
"We're just collecting data," said Leslie McFarlane, disease coordinator for the DWR. "Looking at their body condition overall, they're all looking great so far, but we have to wait for test results to be sure."
The primary concern with relocating bighorns is pneumonia, which has killed around 1,000 of the animals in recent years in several Western states, including Utah. The primary cause for the outbreaks has been transmission of pneumonia-causing bacteria from domestic sheep to wild ones.
The Antelope Island sheep are California bighorns, a lighter-horned subspecies of the Rocky Mountain bighorn. Utah is now home to an estimated 2,200 Rocky Mountain bighorns in the northern and central part of the state, and 2,000 desert bighorns in Southern Utah.
Steve Sorenson, a volunteer with Sportsmen for Fish and Wildlife, said keeping pneumonia from spreading to bighorn populations that haven't been affected is the top priority.
"We want to see more of them around the state," he said of the bighorns. "The problem is when they get next to domestic sheep. It's a big problem all across the West."
In addition to helping maintain enough healthy habitat for all of Antelope Island's animal residents, the relocation effort will also establish a brand-new herd of bighorns.
"There's an intrinsic value to it," said Riley Peck, DWR wildlife biologist for the area where the sheep will be released. "People love to see them."
Peck said he also hopes a bighorn hunt can be started in the area once the herd is established.
When the captured sheep receive a clean bill of health, they will be released into their new home.
Then, Dave and his herd mates will be able to run free once again.