What's eating the baby elk?

By SCOTT McMILLION Chronicle Staff Writer

YELLOWSTONE NATIONAL PARK, Wyo. -- The tiny jawbone lay there by itself on a log still black from a fire 16 years ago, the little teeth just emerging from the bone, still a bit pink but stripped entirely clean of any type of meat.

A footstep away, the crest of the elk calf's skull gleamed stark white in a dewy bed of green grass. Powerful jaws had broken it apart. A hungry mouth had sucked it clean.

Two more paces away, the calf's hide lay tangled beneath another log in the snarl of toppled snags and new lodgepoles twisting up through them. There wasn't a bit of flesh on it.

"That's what we call a banana peel," said Shannon Barber, who is working on a three-year research project to find out what is killing elk calves here.

The scene was typical of how a bear devours a carcass: It peels off the hide and eats everything in it but the bones, she said.

"The banana-peel action," Barber repeated.

Wolves eat differently, she said. "They just rip it to shreds."

The bear had been efficient.

A tiny radio transmitter on the calf's ear had shown it was alive and moving the previous evening. By 9:30 that morning, the roughly 50-pound, 11-day-old animal had been reduced to bone and hide. Even the ear that had carried the transmitter was gone. Bear scat the size of dinner plates surrounded the kill.

"It was alive yesterday afternoon," Barber said. "It probably died yesterday evening or early this morning."

Barber works under renowned wolf expert David Mech. She and two park volunteers, Vince Green and Michelle St. Martin, are spending their days together in the field during Yellowstone's rainiest months, from the middle of May until the middle of July.

They rise early, assemble in a Mammoth Hot Springs parking lot at 7 a.m., and wait for a report from a pilot circling the park's northern range. During the first part of this year's field work, a total of 44 calves were captured and fitted with the transmitters.

These calves were caught within the first five days of their life, sometimes by crews cruising the park's roads, sometimes by biologists in a helicopter, said P.J. White, a National Park Service wildlife biologist.

Generally, the babies remain quiet during the handling. But sometimes they kick.

"And sometimes they take off like Secretariat," White said.

For the next year, the young elk will be monitored. When one of them doesn't move for four hours, the 20-gram transmitter begins sending out a "mortality signal."

Last Friday, the pilot located four such signals.

The first animal, found earlier that morning, was a bit of a mystery. Lying dead on its side along the Gardner River, within site of the motels and restaurants of Gardiner, it showed no immediate sign of injury. Nothing had tried to eat it, not even a raven.

The three reasearchers donned rubber gloves and examined the carcass, quickly locating tears and abrasions on the left hanch. They looked like bite marks.

Electronic calipers measured the wounds while the crew speculated about the cause of death. A fall perhaps, but most likely a coyote. The calf's mother stood 50 feet away, watchful and worried, but not aggressive.

"It probably got bit up there," Barber said, gesturing to the dry benches above the loud and rushing stream. "Then came down here to rest, and it died."

Once the field notes were taken, Green carried the carcass on his shoulders to a vehicle a half-mile away. The crew had wrapped the body in garbage bags, helping to disguise their burden from its mother.

"I really hate taking it away from its mother," Barber said. "That really sucks."

Three days later a necropsy, an autopsy for animals, would confirm Barber's suspicions about the cause of death. The bite marks were consistent with a coyote attack. There was deep tissue hemmhorage, meaning the calf might have lost the use of one hind leg, making it difficult or impossible to nurse. The wound was a few days old and had begun to heal, but there could have been infection, too.

The wound, the stress, the snow and cold wind the day before -- maybe it all added up.

"It just succumbed," Barber said.

The cause of death would be recorded as "possible coyote."

Later that same day, after a long hike through deadfall, the crew found a third carcass. That one probably fell to wolves. An analysis of scat to be done in a lab later would give more evidence, but Barber said, "It smelled like wolf scat."

It's part of her job to know the difference, to put her nose next to a fresh pile and determine if it passed through a wolf, a coyote or a bear.

All have distinct odors, she said.

The crew works hard, but stays in high spirits, talking about yesterday's ball game and issuing congratulations when somebody spots a carcass in particularly thick cover.

And the study they're working on, now in its second of three years, is an important one.

Since wolves were restored in Yellowstone in 1995 and 1996, elk calf suvival ratios have declined sharply and the size of the Northern Yellowstone elk herd has dropped by more than 50 percent.

Many blame wolves for the decline, but other factors are at work.

This year's field work is far from complete so there are no new statistics, but last year's preliminary data showed that bears, particularly grizzlies, take more young elk calves than any other predator.

Of last year's 50 radio-monitored calves, grizzlies took 10, black bears took five and unknown species of bears took four more. Most were killed within the calves' first two weeks of life, when their survival mechanism is to hide instead of to flee.

Other predators -- wolves, coyotes, lions and one wolverine -- took anther 13 of the 50 calves by last October. In total, carnivores killed 64 percent of the total by autumn.

Between October and May, only two more of the original 50 had died. A hunter shot one outside the park and another fell to coyotes.

White said he was a little surprised that more calves didn't fall to wolves over the winter. That might be because most of the study animals migrated out of the park, where there are fewer wolves and "the risk of predation from wolves is less."

In all, the first year's study group had a one-year survival rate of 28 percent, about three times the average for all the northern range for the past three years.

The goal of the study is to shed light on one part of the never-ending debates around wolves: Do the calves killed by wolves add to the number taken by bears and other predators? Or do the wolves take animals that likely would have fed some other carnivore?

In the language of biology, its a matter of "additive" or "compensatory" predation.

Getting to the answer takes the hard work of Barber and her crew, people who know what it means when they find a banana peel in the woods.

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