Goliaths of the Bighorns

Funding brings Game and Fish and UW researchers together for first Bighorn mountain range moose study

Posted 8/16/18

By air and on foot, scientists have now finished capturing and collaring 60 moose in the Bighorn Mountains with sophisticated transmitters for the range’s first study of the storied …

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Goliaths of the Bighorns

Funding brings Game and Fish and UW researchers together for first Bighorn mountain range moose study


By air and on foot, scientists have now finished capturing and collaring 60 moose in the Bighorn Mountains with sophisticated transmitters for the range’s first study of the storied species.

The culmination of the collaring effort by state biologists, researchers and game wardens, is the first step in understanding the population, which was translocated to the Bighorns beginning in 1948. The study may also contain answers to other herds in the state, helping scientists understand why the species is struggling.

“In most of Wyoming, moose are in decline,” said Leslie Schreiber, Greybull area wildlife biologist and the lead for the collaring project on the west side of the range.

Yet in the Bighorns, moose have never been studied, Schreiber said. Without research, very little is known about the numbers and health of the herd. And it’s hard to protect what you don’t know, Schreiber said.

Previous proposals to examine the herd lacked the funds for the expensive effort. But last year, more than $240,000 was made available for collars and resources for the first year of the study. The Game and Fish department will fund the bulk of the costs, said Peter Dube, commissioner from Buffalo. They were also helped with donations from contributors Wyoming Governors Big Game License Coalition and the Sheridan County Sportsman’s Association.

“There’s so much we need to know. These [scientists] do an amazing job and it makes the commission’s job easier when our folks have more tools in their tool kit,” Dube said.

The first step

The collaring team consists of biologists and game wardens from the Game and Fish and researchers from the Wyoming Cooperative Fish and Wildlife Research Unit at the University of Wyoming, who are working in collaboration with the department to interpret data collected from the study. The team worked both from the air and on the ground, said Dan Thiele, Game and Fish wildlife management coordinator in Sheridan.

About half of the moose — all cows — were netted from helicopters in inaccessible areas. The other half was pursued on foot by teams armed with tranquilizers. The collaring effort began in March 2017, continued in February and then finished this month. The last of the 60 collars available for the study were installed in a final push last week.

Collars can only be installed when cows aren’t nursing calves, to ensure the drugs used don’t transfer through milk. A combination of three drugs known as BAM — butorphanol tartrate, azaperone tartrate and medetomidine hydrochloride — is used to immobilize the cows. The dosages used don’t render the moose unconscious, immobilizing them just enough to allow scientists to do tests without being a danger to the moose. A blindfold — often a T-shirt — is used to further calm the cow.

Capturing the cows from the air is efficient, Thiele said. But ground efforts more resemble an actual hunt, where anything can happen. On Monday, hoping to install the final three collars available, the team was up well before sunrise. Two females were located near Bald Mountain in the northern part of the range and the hunt was on.

Schreiber and habitat access technician Eric Shorma took the lead with the dart guns. The moose were in a good position early in the hunt, but headed for the woods as soon as they saw the team closing in. As the sun broke over the trees, the team caught up to the trio in a heavily overgrown riparian area, but couldn’t fire while the moose were near the creek. If a tranquilized moose went down in the creek, it could easily drown.

The team pursued the moose to an opening in the trees, but as the two shooters tried to get into position, the bull kept moving to protect the cows. The shooters had to keep a safe distance — moose are one of the most dangerous animals in Wyoming — yet they needed to be within 30 yards for the shot.

After about two hours, the team called off the chase. Dejection about the missed opportunity lasted only a few seconds as they scrambled to search for a new subject. They had to act fast to get the job done before the heat of the day set in.

The team caught up to a cow near the Porcupine Creek Ranger Station; it was feeding with two calves in a field near a stand of pines. Shorma quickly moved into position and darted the cow in the hindquarters. Then the team had to wait until the drugs took effect. Ten minutes passed before it was obvious the cow would go down. Her two calves surrounded her and tried to keep her up. They stayed with her as she gently laid down and within a minute, the team moved in.

The calves headed to the edge of the woods while the scientists quickly ran their tests. In every operation involving calves, the young animals watch from a nearby location or lie down near their mother, Schreiber said.

The team worked fast. After the cow is down, the team races in to support the moose. They have to keep the animal upright to keep it from choking. They also have to make sure the moose doesn’t overheat, so the operations can only be done in early morning and late evening hours.

The workers draw blood, pull hair, take a fecal sample and check for parasites — especially ticks.

“In Maine, moose are declining and it’s probably because of heavy tick loads. In the spring, when ticks feed for the first time, they can drain a moose dry,” Schreiber said. “A horrible way to die.”

Schreiber hasn’t been seeing a tick problem in two seasons of working moose in the Bighorns. But moose in Wyoming face many challenges including internal parasites, predation and the fragmentation of their habitats. Researchers won’t know the challenges of the Bighorn herd until they’ve had the chance to study them.

`Look — she's wearing a necklace´

After the tests, the team installed the collar. It has to be tight enough to stay on, but loose enough to account for the winter coat, Schreiber said. Attached to the collars are satellite transmitters, which give real-time location for about three years.

As soon as tests were complete and the collar secured, the cow was given another shot to reverse the effects of BAM. The team combed the cow for injuries while she began to regain her strength. They then moved to a safe distance to wait for her to get up. She was munching on bushes before standing.

Most of the team moved on to look for another cow, but Schreiber stayed behind to make sure the calves were reunited with their mother.

A short time later, the calves tentatively appeared from the woods and, after a little nuzzling, they all began to feed again. A car full of passing tourists stopped when they saw the trio. A little girl in the back seat, barely tall enough to see out the window, said, “Look — she’s wearing a necklace.”

Collecting the data

For the next three years, the cows will be observed and data about their health, birth rates and movements will be collected to help scientists estimate the population, understand the carrying capacity of the ecosystem and the health of the herd and habitat. The data will not only help with the Bighorn herd, but will assist research being done by other study teams, Dube said.

“A lot of these projects have other studies piggybacking on their work. You capture a specimen and you get hair, blood and information from a variety of tests. Sometimes others are studying the animals and they just need some blood [or other data]. Capturing that one animal can lead to a variety of different studies,” Dube said.

Studies of other Wyoming herds have been going for decades, said Schreiber. It’s too early to know the exact benefits of the Bighorn study, but after three years, a timer in the collars will expire, releasing the device and falling to the ground. Using GPS transmissions, the collars will be collected, refurbished and used in other studies.

“The advances in the science of these collars are amazing,” Dube said. “They’ve contributed a lot to our knowledge of many different species in the state. It’s very, very important work.”

Commissioner Dube assisted a team collaring moose in the southern part of the Bighorns earlier this month. It wasn’t his first trip to help scientists. He’s also worked on cooperative projects with UW’s Dr. Kevin Monteith’s team on deer, coyote and elk studies. Dube is hands-on while attempting to better understand the issues Game and Fish employees and UW researchers face daily.

“The people from the Game and Fish and the University of Wyoming are very devoted individuals. They spend a lot of time working overtime on nights, weekends, whatever it takes. They do an outstanding job, from top to bottom,” Dube said. “They not only care for the state’s wildlife, but they keep the public informed.”

Bighorn range cows are off limits to hunters during the study. Due to the declining populations, the number of tags issued has dropped from nearly 20 a few seasons ago to just five for this season, Thiele said.

The team needs assistance from the public, Schreiber said.

“People can help us,” she said. “If they’re in the Bighorns and they see a moose with a collar on it and it has a calf, that’s valuable information.”

If you see a collared moose, call the Cody office of the Game and Fish at 307-527-7125 or the Sheridan office at 307-672-7418.