FILER -- "Watch your back," yelled Dr. Ted Rea to his son, Austin, and two other 18-year-old boys.

The boys whirled and as a show of force they yelled and waved 5-foot sticks in the air. The cow elk halted her charge, but she didn't retreat, instead she stamped a foot. Her teeth clicked, her tongue protruded, the slits beneath her eyes opened causing her eyes to appear nearly twice their normal size. The boys checked the canyon terrain for a rock to climb in case she charged again.

"She's a nasty one," Austin said.

"No. She's a good mother," said Ted, defending one of his 27 cow elk. The cow was defending the herd's calves as this crew tried to find and tag newborns.

Rea, a doctor of gastroenterology, wants good mothers since he has sidelined from endoscopying humans to raising elk.

Raised in Texas, Ted graduated from the University of Texas Medical Branch in 1975. He spent 18 years practicing medicine in College State, Texas. Six years ago, he joined a practice in Twin Falls so he could acquire property suitable to raising wildlife.

The canyon property the Reas bought had lava rock cliffs, lakes, streams, and a collection of junk people had dumped over the rim.

"You can't believe how many bedsprings I hauled out of here," Ted said.

For more than three years, Ted, Molly, his wife of 25 years, and their two children, Austin and Natalie lived in a single-wide trailer parked close to their future home. Molly worked with an architect to design what Ted says is a home equivalent to "a tuxedo shirt worn with a pair of blue jeans." Using timbers from an old bean factory, they built what they hope is a dwelling that enhances the outdoors and brings nature into the living space. The 8-foot high elk fences are within 65 feet of the house.

"Instead of wind chimes, we have elk," said Molly as the herd bugles into the evening sky.

"Next year we'll calf out in the field," explained Ted referring to pasture land east of Filer.

He is readying his Filer property with a high fence, three sprinkler pivots, several thousand saplings, and a grass mixture especially designed for elk. Less picturesque than the canyon property where calving occurred this year, the flat land will be safer for tagging calves. The present calving location amongst rugged rock formations and tall reeds next to hidden lakes, provides countless hiding spots for cow elk to camouflage their young.

Normally, elk give birth in the heat of the day and tagging must be done before the calf gets up and joins the mother, typically within 24 hours.

Someone must hold the newborn's mouth closed while an ear tag is inserted.

"If the calf squeals," Molly said, "mothers come from all over."

"Gives you a thrill," said Austin about elk charging and rearing up on hind legs to strike out with front hooves. "You have to be a good rock climber."

Molly motions to the young men looking for babies. Cautiously the troop of three edge through rock outcrops, sticks raised to fight off an attacking mother. "We use 18-year-old boys," she said with a laugh, "because they have no sense of their own mortality. Us and Uncle Sam send them in to do battle."

Tagging the young is only a small part of raising elk. Ted would like to help pioneer new techniques of embryo transplants within elk. Because elk have an elongated cervix, harvesting embryos has been difficult and costly. He feels that the techniques and fiber optics he uses in gastroenterology are well-suited to artificial insemination and transplants.

"We understand the hormonal events pretty well," he said, "but mostly we've been going in blind. In a day when we can see 27 feet of a human's small intestinal track, it's not a big leap to examine an elk's endometrial cavity with a scope."

A registered nurse, Molly's medical speculation is a bit different from her husband's. She wonders if there could be human application in studying elk antlers. These antlers are the fastest growing tissue known in mammals. If such nerve growth could be reproduced, Molly proposes that the growth potential could help with spinal cord injuries.

The Reas have had ample opportunity to watch elk antlers grow as two of their three bulls are winners of the North American Elk Breeders' Association's International Competition. As a 2-year-old, their bull, Matador, had the largest typical hard horn as determined by the Safari Club Scoring. As a 3-year-old, their bull, Excaliber, was second place in the world.

Ted not only buys stock for their genetic potential, but he buys from a closed herd to lessen his risk of having an animal with Chronic Wasting Disease. He feels that elk ranchers and farmers have been aggressive in eradicating the disease within their herds. For the last 10 years every elk death has been analyzed for CWD.

"When there is live animal assesses, things will change," he said.

He explains that there are promising studies being conducted to detect CWD in live animals. He feels that the increase in economic interest in elk will help promote the studies.

"Wouldn't it be ironic if a scenario occurred where the wild herds had to be repopulated with animals from the captive herds?" Ted posed while surveying the animals he loves.

This doctor and elk farmer does love these animals. He describes them as incredibly bright animals with individual personalities.

"I don't want to humanize them or project human traits on them," he said, "but they have a complex society."

The elk owner explained that there is a herd cow and always one of the mothers is standing guard as the baby-sitter.

Disposition notwithstanding, Ted feels that elk have many advantages over other livestock. He claims they are more environmentally friendly. Three elk can survive on the same pasture it would take to sustain one cow. More attuned to the season, elk's energy needs drastically diminish in the winter. Because they are so efficient, they produce less waste, hence less smell.

Raising these 450-650 pound animals is an offshoot of his love of the outdoors. Ted has spent countless hours hunting various animals. His home is decorated with mounted animals that include a stuffed grizzly he shot in Alaska, a nyala he got in Zulu, a lion that once lived in Tanzania, and a spring box he got in Mozambique. The raccoon was bagged by the family dog.

"Now I get to see them not just during hunting season, but I get to work with them every day," Ted said. "I get to watch the birth, watch them protect their young, understand their nutritional requirements. I enjoy every minute of it."

With his love for the animal, Ted admits that it's a complicated thought process to consider that he is producing a product that could eventually be hunted. Yet, he feels strongly that as he plants trees and grasses for his elk, he is producing a habitat that benefits all wildlife -- birds, deer, fox, and rabbits to name a few.

"This type of agriculture persists in enhancing habitat for both species -- man and elk," Ted said. "It's a marvelous way for man to co-exist and break the cycle of ag diminishing habitat for wildlife. Rather than agriculture practices destroying natural habitat, this type of agriculture practices increases habitat."

With wildlife being raised by the private sector, Ted feels that pressure on national parks and public hunting grounds can be reduced. Government will no longer have the soul responsibility of improving wildlife.

Individuals, he said, are "empirically much more selective of what is harvested than in an unregulated ecosystem. It is reported that wolves kill off the weak. Sure they do. Weak ones are the yearling and the newborn. Wolves will kill anything they can. In a trophy-hunt model, elk survive long enough to propagate their genetic potential."

Meanwhile the elk bugle to one another in the gathering dusk.

"Are they going to keep me up all night?" asked Natalie, 16.

"Think of it as a serenade," said her father. He does.